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2013 |
Quintin, Jessica; Asmar, Joelle; Matskevich, Alexey A; Lafarge, Marie-Céline; Ferrandon, Dominique The Drosophila Toll pathway controls but does not clear Candida glabrata infections Article de journal J. Immunol., 190 (6), p. 2818–2827, 2013, ISSN: 1550-6606. Résumé | Liens | BibTeX | Étiquettes: Adaptor Proteins, Animal, Animals, Antigens, Candida glabrata, Candidiasis, Cells, Cultured, Differentiation, Disease Models, ferrandon, Immunologic, M3i, Phagocytosis, Receptors, Signal Transducing, Signal Transduction, Toll-Like Receptors, Virulence @article{quintin_drosophila_2013b, title = {The Drosophila Toll pathway controls but does not clear Candida glabrata infections}, author = {Jessica Quintin and Joelle Asmar and Alexey A Matskevich and Marie-Céline Lafarge and Dominique Ferrandon}, doi = {10.4049/jimmunol.1201861}, issn = {1550-6606}, year = {2013}, date = {2013-03-01}, journal = {J. Immunol.}, volume = {190}, number = {6}, pages = {2818--2827}, abstract = {The pathogenicity of Candida glabrata to patients remains poorly understood for lack of convenient animal models to screen large numbers of mutants for altered virulence. In this study, we explore the minihost model Drosophila melanogaster from the dual perspective of host and pathogen. As in vertebrates, wild-type flies contain C. glabrata systemic infections yet are unable to kill the injected yeasts. As for other fungal infections in Drosophila, the Toll pathway restrains C. glabrata proliferation. Persistent C. glabrata yeasts in wild-type flies do not appear to be able to take shelter in hemocytes from the action of the Toll pathway, the effectors of which remain to be identified. Toll pathway mutant flies succumb to injected C. glabrata. In this immunosuppressed background, cellular defenses provide a residual level of protection. Although both the Gram-negative binding protein 3 pattern recognition receptor and the Persephone protease-dependent detection pathway are required for Toll pathway activation by C. glabrata, only GNBP3, and not psh mutants, are susceptible to the infection. Both Candida albicans and C. glabrata are restrained by the Toll pathway, yet the comparative study of phenoloxidase activation reveals a differential activity of the Toll pathway against these two fungal pathogens. Finally, we establish that the high-osmolarity glycerol pathway and yapsins are required for virulence of C. glabrata in this model. Unexpectedly, yapsins do not appear to be required to counteract the cellular immune response but are needed for the colonization of the wild-type host.}, keywords = {Adaptor Proteins, Animal, Animals, Antigens, Candida glabrata, Candidiasis, Cells, Cultured, Differentiation, Disease Models, ferrandon, Immunologic, M3i, Phagocytosis, Receptors, Signal Transducing, Signal Transduction, Toll-Like Receptors, Virulence}, pubstate = {published}, tppubtype = {article} } The pathogenicity of Candida glabrata to patients remains poorly understood for lack of convenient animal models to screen large numbers of mutants for altered virulence. In this study, we explore the minihost model Drosophila melanogaster from the dual perspective of host and pathogen. As in vertebrates, wild-type flies contain C. glabrata systemic infections yet are unable to kill the injected yeasts. As for other fungal infections in Drosophila, the Toll pathway restrains C. glabrata proliferation. Persistent C. glabrata yeasts in wild-type flies do not appear to be able to take shelter in hemocytes from the action of the Toll pathway, the effectors of which remain to be identified. Toll pathway mutant flies succumb to injected C. glabrata. In this immunosuppressed background, cellular defenses provide a residual level of protection. Although both the Gram-negative binding protein 3 pattern recognition receptor and the Persephone protease-dependent detection pathway are required for Toll pathway activation by C. glabrata, only GNBP3, and not psh mutants, are susceptible to the infection. Both Candida albicans and C. glabrata are restrained by the Toll pathway, yet the comparative study of phenoloxidase activation reveals a differential activity of the Toll pathway against these two fungal pathogens. Finally, we establish that the high-osmolarity glycerol pathway and yapsins are required for virulence of C. glabrata in this model. Unexpectedly, yapsins do not appear to be required to counteract the cellular immune response but are needed for the colonization of the wild-type host. |
Ayyaz, Arshad; Giammarinaro, Philippe; Liégeois, Samuel; Lestradet, Matthieu; Ferrandon, Dominique Immunobiology, 218 (4), p. 635–644, 2013, ISSN: 1878-3279. Résumé | Liens | BibTeX | Étiquettes: Adaptor Proteins, Animal, Animals, Antigens, Differentiation, Disease Models, ferrandon, Immunity, Immunologic, Innate, Intestinal Diseases, M3i, Mucosal, Mutation, Receptors, Signal Transducing, Staphylococcal Infections, Staphylococcus, Starvation, Toll-Like Receptors @article{ayyaz_negative_2013b, title = {A negative role for MyD88 in the resistance to starvation as revealed in an intestinal infection of Drosophila melanogaster with the Gram-positive bacterium Staphylococcus xylosus}, author = {Arshad Ayyaz and Philippe Giammarinaro and Samuel Liégeois and Matthieu Lestradet and Dominique Ferrandon}, doi = {10.1016/j.imbio.2012.07.027}, issn = {1878-3279}, year = {2013}, date = {2013-01-01}, journal = {Immunobiology}, volume = {218}, number = {4}, pages = {635--644}, abstract = {Drosophila melanogaster is a useful model to investigate mucosal immunity. The immune response to intestinal infections is mediated partly by the Immune deficiency (IMD) pathway, which only gets activated by a type of peptidoglycan lacking in several medically important Gram-positive bacterial species such as Staphylococcus. Thus, the intestinal host defense against such bacterial strains remains poorly known. Here, we have used Staphylococcus xylosus to develop a model of intestinal infections by Gram-positive bacteria. S. xylosus behaves as an opportunistic pathogen in a septic injury model, being able to kill only flies immunodeficient either for the Toll pathway or the cellular response. When ingested, it is controlled by IMD-independent host intestinal defenses, yet flies eventually die. Having excluded an overreaction of the immune response and the action of toxins, we find that flies actually succumb to starvation, likely as a result of a competition for sucrose between the bacteria and the flies. Fat stores of wild-type flies are severely reduced within a day, a period when sucrose is not yet exhausted in the feeding solution. Interestingly, the Toll pathway mutant MyD88 is more resistant to the ingestion of S. xylosus and to starvation than wild-type flies. MyD88 flies do not rapidly deplete their fat stores when starved, in contrast to wild-type flies. Thus, we have uncovered a novel function of MyD88 in the regulation of metabolism that appears to be independent of its known roles in immunity and development.}, keywords = {Adaptor Proteins, Animal, Animals, Antigens, Differentiation, Disease Models, ferrandon, Immunity, Immunologic, Innate, Intestinal Diseases, M3i, Mucosal, Mutation, Receptors, Signal Transducing, Staphylococcal Infections, Staphylococcus, Starvation, Toll-Like Receptors}, pubstate = {published}, tppubtype = {article} } Drosophila melanogaster is a useful model to investigate mucosal immunity. The immune response to intestinal infections is mediated partly by the Immune deficiency (IMD) pathway, which only gets activated by a type of peptidoglycan lacking in several medically important Gram-positive bacterial species such as Staphylococcus. Thus, the intestinal host defense against such bacterial strains remains poorly known. Here, we have used Staphylococcus xylosus to develop a model of intestinal infections by Gram-positive bacteria. S. xylosus behaves as an opportunistic pathogen in a septic injury model, being able to kill only flies immunodeficient either for the Toll pathway or the cellular response. When ingested, it is controlled by IMD-independent host intestinal defenses, yet flies eventually die. Having excluded an overreaction of the immune response and the action of toxins, we find that flies actually succumb to starvation, likely as a result of a competition for sucrose between the bacteria and the flies. Fat stores of wild-type flies are severely reduced within a day, a period when sucrose is not yet exhausted in the feeding solution. Interestingly, the Toll pathway mutant MyD88 is more resistant to the ingestion of S. xylosus and to starvation than wild-type flies. MyD88 flies do not rapidly deplete their fat stores when starved, in contrast to wild-type flies. Thus, we have uncovered a novel function of MyD88 in the regulation of metabolism that appears to be independent of its known roles in immunity and development. |
2012 |
Deleury, Emeline; Dubreuil, Géraldine; Elangovan, Namasivayam; Wajnberg, Eric; Reichhart, Jean-Marc; Gourbal, Benjamin; Duval, David; Baron, Olga Lucia; Gouzy, Jérôme; Coustau, Christine Specific versus non-specific immune responses in an invertebrate species evidenced by a comparative de novo sequencing study Article de journal PLoS ONE, 7 (3), p. e32512, 2012, ISSN: 1932-6203. Résumé | Liens | BibTeX | Étiquettes: Animals, Biomphalaria, Calmodulin, Cluster Analysis, Complementary, DNA, Expressed Sequence Tags, Ferritins, Gene Expression Profiling, Gene Expression Regulation, High-Throughput Nucleotide Sequencing, Immunity, Innate, M3i, messenger, Pattern Recognition, Phylogeny, Receptors, reichhart, RNA, Signal Transduction, Zinc Fingers @article{deleury_specific_2012, title = {Specific versus non-specific immune responses in an invertebrate species evidenced by a comparative de novo sequencing study}, author = {Emeline Deleury and Géraldine Dubreuil and Namasivayam Elangovan and Eric Wajnberg and Jean-Marc Reichhart and Benjamin Gourbal and David Duval and Olga Lucia Baron and Jérôme Gouzy and Christine Coustau}, doi = {10.1371/journal.pone.0032512}, issn = {1932-6203}, year = {2012}, date = {2012-01-01}, journal = {PLoS ONE}, volume = {7}, number = {3}, pages = {e32512}, abstract = {Our present understanding of the functioning and evolutionary history of invertebrate innate immunity derives mostly from studies on a few model species belonging to ecdysozoa. In particular, the characterization of signaling pathways dedicated to specific responses towards fungi and Gram-positive or Gram-negative bacteria in Drosophila melanogaster challenged our original view of a non-specific immunity in invertebrates. However, much remains to be elucidated from lophotrochozoan species. To investigate the global specificity of the immune response in the fresh-water snail Biomphalaria glabrata, we used massive Illumina sequencing of 5'-end cDNAs to compare expression profiles after challenge by Gram-positive or Gram-negative bacteria or after a yeast challenge. 5'-end cDNA sequencing of the libraries yielded over 12 millions high quality reads. To link these short reads to expressed genes, we prepared a reference transcriptomic database through automatic assembly and annotation of the 758,510 redundant sequences (ESTs, mRNAs) of B. glabrata available in public databases. Computational analysis of Illumina reads followed by multivariate analyses allowed identification of 1685 candidate transcripts differentially expressed after an immune challenge, with a two fold ratio between transcripts showing a challenge-specific expression versus a lower or non-specific differential expression. Differential expression has been validated using quantitative PCR for a subset of randomly selected candidates. Predicted functions of annotated candidates (approx. 700 unisequences) belonged to a large extend to similar functional categories or protein types. This work significantly expands upon previous gene discovery and expression studies on B. glabrata and suggests that responses to various pathogens may involve similar immune processes or signaling pathways but different genes belonging to multigenic families. These results raise the question of the importance of gene duplication and acquisition of paralog functional diversity in the evolution of specific invertebrate immune responses.}, keywords = {Animals, Biomphalaria, Calmodulin, Cluster Analysis, Complementary, DNA, Expressed Sequence Tags, Ferritins, Gene Expression Profiling, Gene Expression Regulation, High-Throughput Nucleotide Sequencing, Immunity, Innate, M3i, messenger, Pattern Recognition, Phylogeny, Receptors, reichhart, RNA, Signal Transduction, Zinc Fingers}, pubstate = {published}, tppubtype = {article} } Our present understanding of the functioning and evolutionary history of invertebrate innate immunity derives mostly from studies on a few model species belonging to ecdysozoa. In particular, the characterization of signaling pathways dedicated to specific responses towards fungi and Gram-positive or Gram-negative bacteria in Drosophila melanogaster challenged our original view of a non-specific immunity in invertebrates. However, much remains to be elucidated from lophotrochozoan species. To investigate the global specificity of the immune response in the fresh-water snail Biomphalaria glabrata, we used massive Illumina sequencing of 5'-end cDNAs to compare expression profiles after challenge by Gram-positive or Gram-negative bacteria or after a yeast challenge. 5'-end cDNA sequencing of the libraries yielded over 12 millions high quality reads. To link these short reads to expressed genes, we prepared a reference transcriptomic database through automatic assembly and annotation of the 758,510 redundant sequences (ESTs, mRNAs) of B. glabrata available in public databases. Computational analysis of Illumina reads followed by multivariate analyses allowed identification of 1685 candidate transcripts differentially expressed after an immune challenge, with a two fold ratio between transcripts showing a challenge-specific expression versus a lower or non-specific differential expression. Differential expression has been validated using quantitative PCR for a subset of randomly selected candidates. Predicted functions of annotated candidates (approx. 700 unisequences) belonged to a large extend to similar functional categories or protein types. This work significantly expands upon previous gene discovery and expression studies on B. glabrata and suggests that responses to various pathogens may involve similar immune processes or signaling pathways but different genes belonging to multigenic families. These results raise the question of the importance of gene duplication and acquisition of paralog functional diversity in the evolution of specific invertebrate immune responses. |
2011 |
Nehme, Nadine T; Quintin, Jessica; Cho, Ju Hyun; Lee, Janice; Lafarge, Marie-Céline; Kocks, Christine; Ferrandon, Dominique Relative roles of the cellular and humoral responses in the Drosophila host defense against three gram-positive bacterial infections Article de journal PLoS ONE, 6 (3), p. e14743, 2011, ISSN: 1932-6203. Résumé | Liens | BibTeX | Étiquettes: Animals, Antimicrobial Cationic Peptides, Carrier Proteins, Cell Surface, Cellular, Enterococcus faecalis, ferrandon, Gram-Positive Bacteria, Gram-Positive Bacterial Infections, Host-Pathogen Interactions, Humoral, Immunity, Innate, M3i, Micrococcus luteus, Opsonin Proteins, Phagocytosis, Receptors, Signal Transduction, Solubility, Staphylococcus aureus @article{nehme_relative_2011b, title = {Relative roles of the cellular and humoral responses in the Drosophila host defense against three gram-positive bacterial infections}, author = {Nadine T Nehme and Jessica Quintin and Ju Hyun Cho and Janice Lee and Marie-Céline Lafarge and Christine Kocks and Dominique Ferrandon}, doi = {10.1371/journal.pone.0014743}, issn = {1932-6203}, year = {2011}, date = {2011-01-01}, journal = {PLoS ONE}, volume = {6}, number = {3}, pages = {e14743}, abstract = {BACKGROUND: Two NF-kappaB signaling pathways, Toll and immune deficiency (imd), are required for survival to bacterial infections in Drosophila. In response to septic injury, these pathways mediate rapid transcriptional activation of distinct sets of effector molecules, including antimicrobial peptides, which are important components of a humoral defense response. However, it is less clear to what extent macrophage-like hemocytes contribute to host defense. METHODOLOGY/PRINCIPAL FINDINGS: In order to dissect the relative importance of humoral and cellular defenses after septic injury with three different gram-positive bacteria (Micrococcus luteus, Enterococcus faecalis, Staphylococcus aureus), we used latex bead pre-injection to ablate macrophage function in flies wildtype or mutant for various Toll and imd pathway components. We found that in all three infection models a compromised phagocytic system impaired fly survival--independently of concomitant Toll or imd pathway activation. Our data failed to confirm a role of the PGRP-SA and GNBP1 Pattern Recognition Receptors for phagocytosis of S. aureus. The Drosophila scavenger receptor Eater mediates the phagocytosis by hemocytes or S2 cells of E. faecalis and S. aureus, but not of M. luteus. In the case of M. luteus and E. faecalis, but not S. aureus, decreased survival due to defective phagocytosis could be compensated for by genetically enhancing the humoral immune response. CONCLUSIONS/SIGNIFICANCE: Our results underscore the fundamental importance of both cellular and humoral mechanisms in Drosophila immunity and shed light on the balance between these two arms of host defense depending on the invading pathogen.}, keywords = {Animals, Antimicrobial Cationic Peptides, Carrier Proteins, Cell Surface, Cellular, Enterococcus faecalis, ferrandon, Gram-Positive Bacteria, Gram-Positive Bacterial Infections, Host-Pathogen Interactions, Humoral, Immunity, Innate, M3i, Micrococcus luteus, Opsonin Proteins, Phagocytosis, Receptors, Signal Transduction, Solubility, Staphylococcus aureus}, pubstate = {published}, tppubtype = {article} } BACKGROUND: Two NF-kappaB signaling pathways, Toll and immune deficiency (imd), are required for survival to bacterial infections in Drosophila. In response to septic injury, these pathways mediate rapid transcriptional activation of distinct sets of effector molecules, including antimicrobial peptides, which are important components of a humoral defense response. However, it is less clear to what extent macrophage-like hemocytes contribute to host defense. METHODOLOGY/PRINCIPAL FINDINGS: In order to dissect the relative importance of humoral and cellular defenses after septic injury with three different gram-positive bacteria (Micrococcus luteus, Enterococcus faecalis, Staphylococcus aureus), we used latex bead pre-injection to ablate macrophage function in flies wildtype or mutant for various Toll and imd pathway components. We found that in all three infection models a compromised phagocytic system impaired fly survival--independently of concomitant Toll or imd pathway activation. Our data failed to confirm a role of the PGRP-SA and GNBP1 Pattern Recognition Receptors for phagocytosis of S. aureus. The Drosophila scavenger receptor Eater mediates the phagocytosis by hemocytes or S2 cells of E. faecalis and S. aureus, but not of M. luteus. In the case of M. luteus and E. faecalis, but not S. aureus, decreased survival due to defective phagocytosis could be compensated for by genetically enhancing the humoral immune response. CONCLUSIONS/SIGNIFICANCE: Our results underscore the fundamental importance of both cellular and humoral mechanisms in Drosophila immunity and shed light on the balance between these two arms of host defense depending on the invading pathogen. |
2008 |
Chamy, Laure El; Leclerc, Vincent; Caldelari, Isabelle; Reichhart, Jean-Marc Sensing of 'danger signals' and pathogen-associated molecular patterns defines binary signaling pathways 'upstream' of Toll Article de journal Nat. Immunol., 9 (10), p. 1165–1170, 2008, ISSN: 1529-2916. Résumé | Liens | BibTeX | Étiquettes: Animals, Fungi, Genetically Modified, Gram-Positive Bacteria, Gram-Positive Bacterial Infections, In Situ Hybridization, M3i, Mycoses, Pattern Recognition, Peptide Hydrolases, Receptors, reichhart, Serine Endopeptidases, Signal Transduction, Toll-Like Receptors @article{el_chamy_sensing_2008, title = {Sensing of 'danger signals' and pathogen-associated molecular patterns defines binary signaling pathways 'upstream' of Toll}, author = {Laure El Chamy and Vincent Leclerc and Isabelle Caldelari and Jean-Marc Reichhart}, doi = {10.1038/ni.1643}, issn = {1529-2916}, year = {2008}, date = {2008-10-01}, journal = {Nat. Immunol.}, volume = {9}, number = {10}, pages = {1165--1170}, abstract = {In drosophila, molecular determinants from fungi and Gram-positive bacteria are detected by circulating pattern-recognition receptors. Published findings suggest that such pattern-recognition receptors activate as-yet-unidentified serine-protease cascades that culminate in the cleavage of Spätzle, the endogenous Toll receptor ligand, and trigger the immune response. We demonstrate here that the protease Grass defines a common activation cascade for the detection of fungi and Gram-positive bacteria mediated by pattern-recognition receptors. The serine protease Persephone, shown before to be specific for fungal detection in a cascade activated by secreted fungal proteases, was also required for the sensing of proteases elicited by bacteria in the hemolymph. Hence, Persephone defines a parallel proteolytic cascade activated by 'danger signals' such as abnormal proteolytic activities.}, keywords = {Animals, Fungi, Genetically Modified, Gram-Positive Bacteria, Gram-Positive Bacterial Infections, In Situ Hybridization, M3i, Mycoses, Pattern Recognition, Peptide Hydrolases, Receptors, reichhart, Serine Endopeptidases, Signal Transduction, Toll-Like Receptors}, pubstate = {published}, tppubtype = {article} } In drosophila, molecular determinants from fungi and Gram-positive bacteria are detected by circulating pattern-recognition receptors. Published findings suggest that such pattern-recognition receptors activate as-yet-unidentified serine-protease cascades that culminate in the cleavage of Spätzle, the endogenous Toll receptor ligand, and trigger the immune response. We demonstrate here that the protease Grass defines a common activation cascade for the detection of fungi and Gram-positive bacteria mediated by pattern-recognition receptors. The serine protease Persephone, shown before to be specific for fungal detection in a cascade activated by secreted fungal proteases, was also required for the sensing of proteases elicited by bacteria in the hemolymph. Hence, Persephone defines a parallel proteolytic cascade activated by 'danger signals' such as abnormal proteolytic activities. |
2006 |
Chen, Li-Ying; Wang, Juinn-Chin; Hyvert, Yann; Lin, Hui-Ping; Perrimon, Norbert; Imler, Jean-Luc; Hsu, Jui-Chou Weckle is a zinc finger adaptor of the toll pathway in dorsoventral patterning of the Drosophila embryo Article de journal Current biology: CB, 16 (12), p. 1183–1193, 2006, ISSN: 0960-9822. Résumé | Liens | BibTeX | Étiquettes: Adaptor Proteins, Animals, Antigens, Biological, Body Patterning, Cell Membrane, Differentiation, dimerization, DNA-Binding Proteins, Embryo, Epistasis, Genetic, imler, Immunity, Immunologic, Innate, M3i, Models, Mutation, Nonmammalian, Phenotype, Phosphoproteins, Receptors, Signal Transducing, Toll-Like Receptors, Transcription Factors, Zinc Fingers @article{chen_weckle_2006, title = {Weckle is a zinc finger adaptor of the toll pathway in dorsoventral patterning of the Drosophila embryo}, author = {Li-Ying Chen and Juinn-Chin Wang and Yann Hyvert and Hui-Ping Lin and Norbert Perrimon and Jean-Luc Imler and Jui-Chou Hsu}, doi = {10.1016/j.cub.2006.05.050}, issn = {0960-9822}, year = {2006}, date = {2006-06-01}, journal = {Current biology: CB}, volume = {16}, number = {12}, pages = {1183--1193}, abstract = {BACKGROUND: The Drosophila Toll pathway takes part in both establishment of the embryonic dorsoventral axis and induction of the innate immune response in adults. Upon activation by the cytokine Spätzle, Toll interacts with the adaptor proteins DmMyD88 and Tube and the kinase Pelle and triggers degradation of the inhibitor Cactus, thus allowing the nuclear translocation of the transcription factor Dorsal/Dif. weckle (wek) was previously identified as a new dorsal group gene that encodes a putative zinc finger transcription factor. However, its role in the Toll pathway was unknown. RESULTS: Here, we isolated new wek alleles and demonstrated that cactus is epistatic to wek, which in turn is epistatic to Toll. Consistent with this, Wek localizes to the plasma membrane of embryos, independently of Toll signaling. Wek homodimerizes and associates with Toll. Moreover, Wek binds to and localizes DmMyD88 to the plasma membrane. Thus, Wek acts as an adaptor to assemble/stabilize a Toll/Wek/DmMyD88/Tube complex. Remarkably, unlike the DmMyD88/tube/pelle/cactus gene cassette of the Toll pathway, wek plays a minimal role, if any, in the immune defense against Gram-positive bacteria and fungi. CONCLUSIONS: We conclude that Wek is an adaptor to link Toll and DmMyD88 and is required for efficient recruitment of DmMyD88 to Toll. Unexpectedly, wek is dispensable for innate immune response, thus revealing differences in the Toll-mediated activation of Dorsal in the embryo and Dif in the fat body of adult flies.}, keywords = {Adaptor Proteins, Animals, Antigens, Biological, Body Patterning, Cell Membrane, Differentiation, dimerization, DNA-Binding Proteins, Embryo, Epistasis, Genetic, imler, Immunity, Immunologic, Innate, M3i, Models, Mutation, Nonmammalian, Phenotype, Phosphoproteins, Receptors, Signal Transducing, Toll-Like Receptors, Transcription Factors, Zinc Fingers}, pubstate = {published}, tppubtype = {article} } BACKGROUND: The Drosophila Toll pathway takes part in both establishment of the embryonic dorsoventral axis and induction of the innate immune response in adults. Upon activation by the cytokine Spätzle, Toll interacts with the adaptor proteins DmMyD88 and Tube and the kinase Pelle and triggers degradation of the inhibitor Cactus, thus allowing the nuclear translocation of the transcription factor Dorsal/Dif. weckle (wek) was previously identified as a new dorsal group gene that encodes a putative zinc finger transcription factor. However, its role in the Toll pathway was unknown. RESULTS: Here, we isolated new wek alleles and demonstrated that cactus is epistatic to wek, which in turn is epistatic to Toll. Consistent with this, Wek localizes to the plasma membrane of embryos, independently of Toll signaling. Wek homodimerizes and associates with Toll. Moreover, Wek binds to and localizes DmMyD88 to the plasma membrane. Thus, Wek acts as an adaptor to assemble/stabilize a Toll/Wek/DmMyD88/Tube complex. Remarkably, unlike the DmMyD88/tube/pelle/cactus gene cassette of the Toll pathway, wek plays a minimal role, if any, in the immune defense against Gram-positive bacteria and fungi. CONCLUSIONS: We conclude that Wek is an adaptor to link Toll and DmMyD88 and is required for efficient recruitment of DmMyD88 to Toll. Unexpectedly, wek is dispensable for innate immune response, thus revealing differences in the Toll-mediated activation of Dorsal in the embryo and Dif in the fat body of adult flies. |
2005 |
Kocks, Christine; Cho, Ju Hyun; Nehme, Nadine; Ulvila, Johanna; Pearson, Alan M; Meister, Marie; Strom, Charles; Conto, Stephanie L; Hetru, Charles; Stuart, Lynda M; Stehle, Thilo; Hoffmann, Jules A; Reichhart, Jean-Marc; Ferrandon, Dominique; Rämet, Mika; Ezekowitz, Alan R B Eater, a transmembrane protein mediating phagocytosis of bacterial pathogens in Drosophila Article de journal Cell, 123 (2), p. 335–346, 2005, ISSN: 0092-8674. Résumé | Liens | BibTeX | Étiquettes: Amino Acid, Amino Acid Motifs, Animals, Bacterial Infections, Cell Surface, Embryo, Escherichia coli, ferrandon, Flow Cytometry, Frameshift Mutation, Genes, Histidine, hoffmann, In Situ Hybridization, Insect, Insect Proteins, M3i, Macrophages, Membrane Proteins, messenger, Nonmammalian, Open Reading Frames, Phagocytosis, Receptors, reichhart, RNA, RNA Interference, Sequence Homology, Serratia marcescens @article{kocks_eater_2005, title = {Eater, a transmembrane protein mediating phagocytosis of bacterial pathogens in Drosophila}, author = {Christine Kocks and Ju Hyun Cho and Nadine Nehme and Johanna Ulvila and Alan M Pearson and Marie Meister and Charles Strom and Stephanie L Conto and Charles Hetru and Lynda M Stuart and Thilo Stehle and Jules A Hoffmann and Jean-Marc Reichhart and Dominique Ferrandon and Mika Rämet and Alan R B Ezekowitz}, doi = {10.1016/j.cell.2005.08.034}, issn = {0092-8674}, year = {2005}, date = {2005-10-01}, journal = {Cell}, volume = {123}, number = {2}, pages = {335--346}, abstract = {Phagocytosis is a complex, evolutionarily conserved process that plays a central role in host defense against infection. We have identified a predicted transmembrane protein, Eater, which is involved in phagocytosis in Drosophila. Transcriptional silencing of the eater gene in a macrophage cell line led to a significant reduction in the binding and internalization of bacteria. Moreover, the N terminus of the Eater protein mediated direct microbial binding which could be inhibited with scavenger receptor ligands, acetylated, and oxidized low-density lipoprotein. In vivo, eater expression was restricted to blood cells. Flies lacking the eater gene displayed normal responses in NF-kappaB-like Toll and IMD signaling pathways but showed impaired phagocytosis and decreased survival after bacterial infection. Our results suggest that Eater is a major phagocytic receptor for a broad range of bacterial pathogens in Drosophila and provide a powerful model to address the role of phagocytosis in vivo.}, keywords = {Amino Acid, Amino Acid Motifs, Animals, Bacterial Infections, Cell Surface, Embryo, Escherichia coli, ferrandon, Flow Cytometry, Frameshift Mutation, Genes, Histidine, hoffmann, In Situ Hybridization, Insect, Insect Proteins, M3i, Macrophages, Membrane Proteins, messenger, Nonmammalian, Open Reading Frames, Phagocytosis, Receptors, reichhart, RNA, RNA Interference, Sequence Homology, Serratia marcescens}, pubstate = {published}, tppubtype = {article} } Phagocytosis is a complex, evolutionarily conserved process that plays a central role in host defense against infection. We have identified a predicted transmembrane protein, Eater, which is involved in phagocytosis in Drosophila. Transcriptional silencing of the eater gene in a macrophage cell line led to a significant reduction in the binding and internalization of bacteria. Moreover, the N terminus of the Eater protein mediated direct microbial binding which could be inhibited with scavenger receptor ligands, acetylated, and oxidized low-density lipoprotein. In vivo, eater expression was restricted to blood cells. Flies lacking the eater gene displayed normal responses in NF-kappaB-like Toll and IMD signaling pathways but showed impaired phagocytosis and decreased survival after bacterial infection. Our results suggest that Eater is a major phagocytic receptor for a broad range of bacterial pathogens in Drosophila and provide a powerful model to address the role of phagocytosis in vivo. |
Martinelli, Cosimo; Reichhart, Jean-Marc Evolution and integration of innate immune systems from fruit flies to man: lessons and questions Article de journal J. Endotoxin Res., 11 (4), p. 243–248, 2005, ISSN: 0968-0519. Résumé | Liens | BibTeX | Étiquettes: Animals, Biological Evolution, Cell Surface, Forecasting, Humans, Immunity, Immunological, Innate, M3i, Membrane Glycoproteins, Models, Receptors, reichhart, Signal Transduction, Toll-Like Receptor 5, Toll-Like Receptors @article{martinelli_evolution_2005, title = {Evolution and integration of innate immune systems from fruit flies to man: lessons and questions}, author = {Cosimo Martinelli and Jean-Marc Reichhart}, doi = {10.1179/096805105X37411}, issn = {0968-0519}, year = {2005}, date = {2005-01-01}, journal = {J. Endotoxin Res.}, volume = {11}, number = {4}, pages = {243--248}, abstract = {Despite broad differences in morphology, ecology and behavior, the fruit fly Drosophila melanogaster and humans show a remarkably high degree of conservation for many molecular, cellular, and developmental aspects of their biology. During the last decade, similarities have also been discovered in some of the mechanisms regulating their innate immune system. These parallels regard mainly the Toll-like receptor family and the intracellular signaling pathways involved in the control of the immune response. However, if the overall similarities are important, the detailed pathogen recognition mechanisms differ significantly between fly and humans, highlighting a complicated evolutionary history of the metazoan innate defenses. In this review, we will discuss the main similarities and differences between the two types of organisms. We hope that this current knowledge will be used as a starting point for a more comprehensive view of innate immunity within the broad variety of metazoan phyla.}, keywords = {Animals, Biological Evolution, Cell Surface, Forecasting, Humans, Immunity, Immunological, Innate, M3i, Membrane Glycoproteins, Models, Receptors, reichhart, Signal Transduction, Toll-Like Receptor 5, Toll-Like Receptors}, pubstate = {published}, tppubtype = {article} } Despite broad differences in morphology, ecology and behavior, the fruit fly Drosophila melanogaster and humans show a remarkably high degree of conservation for many molecular, cellular, and developmental aspects of their biology. During the last decade, similarities have also been discovered in some of the mechanisms regulating their innate immune system. These parallels regard mainly the Toll-like receptor family and the intracellular signaling pathways involved in the control of the immune response. However, if the overall similarities are important, the detailed pathogen recognition mechanisms differ significantly between fly and humans, highlighting a complicated evolutionary history of the metazoan innate defenses. In this review, we will discuss the main similarities and differences between the two types of organisms. We hope that this current knowledge will be used as a starting point for a more comprehensive view of innate immunity within the broad variety of metazoan phyla. |
Weber, Alexander N R; Moncrieffe, Martin C; Gangloff, Monique; Imler, Jean-Luc; Gay, Nicholas J Ligand-receptor and receptor-receptor interactions act in concert to activate signaling in the Drosophila toll pathway Article de journal The Journal of Biological Chemistry, 280 (24), p. 22793–22799, 2005, ISSN: 0021-9258. Résumé | Liens | BibTeX | Étiquettes: Amino Acid, Animals, Biophysical Phenomena, Biophysics, Body Patterning, Calorimetry, Cell Line, Cell Surface, Cross-Linking Reagents, Cytokines, dimerization, Electrophoresis, Humans, imler, ligands, Luciferases, M3i, Membrane Glycoproteins, Polyacrylamide Gel, Protein Binding, Protein Structure, Receptors, Recombinant Proteins, Sequence Homology, Signal Transduction, Tertiary, Time Factors, Toll-Like Receptors, Ultracentrifugation @article{weber_ligand-receptor_2005, title = {Ligand-receptor and receptor-receptor interactions act in concert to activate signaling in the Drosophila toll pathway}, author = {Alexander N R Weber and Martin C Moncrieffe and Monique Gangloff and Jean-Luc Imler and Nicholas J Gay}, doi = {10.1074/jbc.M502074200}, issn = {0021-9258}, year = {2005}, date = {2005-01-01}, journal = {The Journal of Biological Chemistry}, volume = {280}, number = {24}, pages = {22793--22799}, abstract = {In Drosophila, the signaling pathway mediated by the Toll receptor is critical for the establishment of embryonic dorso-ventral pattern and for innate immune responses to bacterial and fungal pathogens. Toll is activated by high affinity binding of the cytokine Spätzle, a dimeric ligand of the cystine knot family. In vertebrates, a related family of Toll-like receptors play a critical role in innate immune responses. Despite the importance of this family of receptors, little is known about the biochemical events that lead to receptor activation and signaling. Here, we show that Spätzle binds to the N-terminal region of Toll and, using biophysical methods, that the binding is complex. The two binding events that cause formation of the cross-linked complex are non-equivalent: the first Toll ectodomain binds Spätzle with an affinity 3-fold higher than the second molecule suggesting that pathway activation involves negative cooperativity. We further show that the Toll ectodomains are able to form low affinity dimers in solution and that juxtamembrane sequences of Toll are critical for the activation or derepression of the pathway. These results, taken together, suggest a mechanism of signal transduction that requires both ligand-receptor and receptor-receptor interactions.}, keywords = {Amino Acid, Animals, Biophysical Phenomena, Biophysics, Body Patterning, Calorimetry, Cell Line, Cell Surface, Cross-Linking Reagents, Cytokines, dimerization, Electrophoresis, Humans, imler, ligands, Luciferases, M3i, Membrane Glycoproteins, Polyacrylamide Gel, Protein Binding, Protein Structure, Receptors, Recombinant Proteins, Sequence Homology, Signal Transduction, Tertiary, Time Factors, Toll-Like Receptors, Ultracentrifugation}, pubstate = {published}, tppubtype = {article} } In Drosophila, the signaling pathway mediated by the Toll receptor is critical for the establishment of embryonic dorso-ventral pattern and for innate immune responses to bacterial and fungal pathogens. Toll is activated by high affinity binding of the cytokine Spätzle, a dimeric ligand of the cystine knot family. In vertebrates, a related family of Toll-like receptors play a critical role in innate immune responses. Despite the importance of this family of receptors, little is known about the biochemical events that lead to receptor activation and signaling. Here, we show that Spätzle binds to the N-terminal region of Toll and, using biophysical methods, that the binding is complex. The two binding events that cause formation of the cross-linked complex are non-equivalent: the first Toll ectodomain binds Spätzle with an affinity 3-fold higher than the second molecule suggesting that pathway activation involves negative cooperativity. We further show that the Toll ectodomains are able to form low affinity dimers in solution and that juxtamembrane sequences of Toll are critical for the activation or derepression of the pathway. These results, taken together, suggest a mechanism of signal transduction that requires both ligand-receptor and receptor-receptor interactions. |
2004 |
Bischoff, Vincent; Vignal, Cécile; Boneca, Ivo G; Michel, Tatiana; Hoffmann, Jules A; Royet, Julien Function of the drosophila pattern-recognition receptor PGRP-SD in the detection of Gram-positive bacteria Article de journal Nat. Immunol., 5 (11), p. 1175–1180, 2004, ISSN: 1529-2908. Résumé | Liens | BibTeX | Étiquettes: Animals, Carrier Proteins, Cell Surface, Gram-Positive Bacteria, Gram-Positive Bacterial Infections, hoffmann, M3i, Mutation, Mycoses, Receptors, Staphylococcus aureus, Toll-Like Receptors @article{bischoff_function_2004, title = {Function of the drosophila pattern-recognition receptor PGRP-SD in the detection of Gram-positive bacteria}, author = {Vincent Bischoff and Cécile Vignal and Ivo G Boneca and Tatiana Michel and Jules A Hoffmann and Julien Royet}, doi = {10.1038/ni1123}, issn = {1529-2908}, year = {2004}, date = {2004-11-01}, journal = {Nat. Immunol.}, volume = {5}, number = {11}, pages = {1175--1180}, abstract = {The activation of an immune response requires recognition of microorganisms by host receptors. In drosophila, detection of Gram-positive bacteria is mediated by cooperation between the peptidoglycan-recognition protein-SA (PGRP-SA) and Gram-negative binding protein 1 (GNBP1) proteins. Here we show that some Gram-positive bacterial species activate an immune response in a PGRP-SA- and GNBP1-independent manner, indicating that alternative receptors exist. Consistent with this, we noted that PGRP-SD mutants were susceptible to some Gram-positive bacteria and that a loss-of-function mutation in PGRP-SD severely exacerbated the PGRP-SA and GNBP1 mutant phenotypes. These data indicate that PGRP-SD can function as a receptor for Gram-positive bacteria and shows partial redundancy with the PGRP-SA-GNBP1 complex.}, keywords = {Animals, Carrier Proteins, Cell Surface, Gram-Positive Bacteria, Gram-Positive Bacterial Infections, hoffmann, M3i, Mutation, Mycoses, Receptors, Staphylococcus aureus, Toll-Like Receptors}, pubstate = {published}, tppubtype = {article} } The activation of an immune response requires recognition of microorganisms by host receptors. In drosophila, detection of Gram-positive bacteria is mediated by cooperation between the peptidoglycan-recognition protein-SA (PGRP-SA) and Gram-negative binding protein 1 (GNBP1) proteins. Here we show that some Gram-positive bacterial species activate an immune response in a PGRP-SA- and GNBP1-independent manner, indicating that alternative receptors exist. Consistent with this, we noted that PGRP-SD mutants were susceptible to some Gram-positive bacteria and that a loss-of-function mutation in PGRP-SD severely exacerbated the PGRP-SA and GNBP1 mutant phenotypes. These data indicate that PGRP-SD can function as a receptor for Gram-positive bacteria and shows partial redundancy with the PGRP-SA-GNBP1 complex. |
Leclerc, Vincent; Reichhart, Jean-Marc The immune response of Drosophila melanogaster Article de journal Immunol. Rev., 198 , p. 59–71, 2004, ISSN: 0105-2896. Résumé | BibTeX | Étiquettes: Animals, Cell Surface, Immunity, Immunological, Innate, M3i, Models, Receptors, reichhart, Signal Transduction, Toll-Like Receptors @article{leclerc_immune_2004, title = {The immune response of Drosophila melanogaster}, author = {Vincent Leclerc and Jean-Marc Reichhart}, issn = {0105-2896}, year = {2004}, date = {2004-04-01}, journal = {Immunol. Rev.}, volume = {198}, pages = {59--71}, abstract = {The response of the fruit fly Drosophila melanogaster to various microorganism infections relies on a multilayered defense. The epithelia constitute a first and efficient barrier. Innate immunity is activated when microorganisms succeed in entering the body cavity of the fly. Invading microorganisms are killed by the combined action of cellular and humoral processes. They are phagocytosed by specialized blood cells, surrounded by toxic melanin, or lysed by antibacterial peptides secreted into the hemolymph by fat body cells. During the last few years, research has focused on the mechanisms of microbial recognition by various pattern recognition receptors and of the subsequent induction of antimicrobial peptide expression. The cellular arm of the Drosophila innate immune system, which was somehow neglected, now constitutes the new frontier.}, keywords = {Animals, Cell Surface, Immunity, Immunological, Innate, M3i, Models, Receptors, reichhart, Signal Transduction, Toll-Like Receptors}, pubstate = {published}, tppubtype = {article} } The response of the fruit fly Drosophila melanogaster to various microorganism infections relies on a multilayered defense. The epithelia constitute a first and efficient barrier. Innate immunity is activated when microorganisms succeed in entering the body cavity of the fly. Invading microorganisms are killed by the combined action of cellular and humoral processes. They are phagocytosed by specialized blood cells, surrounded by toxic melanin, or lysed by antibacterial peptides secreted into the hemolymph by fat body cells. During the last few years, research has focused on the mechanisms of microbial recognition by various pattern recognition receptors and of the subsequent induction of antimicrobial peptide expression. The cellular arm of the Drosophila innate immune system, which was somehow neglected, now constitutes the new frontier. |
Ferrandon, Dominique; Imler, Jean-Luc; Hoffmann, Jules A Sensing infection in Drosophila: Toll and beyond Article de journal Semin Immunol, 16 , p. 43–53, 2004, ISSN: 1044-5323. Résumé | BibTeX | Étiquettes: Animals, Carrier Proteins/chemistry/immunology/physiology, Cell Surface/immunology/*physiology, Drosophila Proteins/chemistry/immunology/*physiology, Drosophila/genetics/*immunology/microbiology, ferrandon, Fungi/immunology, Gene Expression Regulation, Gram-Negative Bacterial Infections/immunology, Gram-Positive Bacterial Infections/immunology, hoffmann, imler, Immunological, Insect Proteins/chemistry/immunology/physiology, M3i, Models, Non-U.S. Gov't, Receptors, Signal Transduction/immunology/physiology, Support @article{ferrandon_sensing_2004b, title = {Sensing infection in Drosophila: Toll and beyond}, author = {Dominique Ferrandon and Jean-Luc Imler and Jules A Hoffmann}, issn = {1044-5323}, year = {2004}, date = {2004-01-01}, journal = {Semin Immunol}, volume = {16}, pages = {43--53}, abstract = {Drosophila has evolved a potent immune system that is somewhat adapted to the nature of infections through the selective activation of either one of two NF-kappa B-like signalling pathways, the Toll and IMD (Immune deficiency) pathways. In contrast to the mammalian system, the Toll receptor does not act as a pattern recognition receptor (PRR) but as a cytokine receptor. The sensing of microbial infections is achieved by at least four PRRs that belong to two distinct families: the peptidoglycan recognition proteins (PGRPs) and the Gram-negative binding proteins (GNBPs)/beta-glucan recognition proteins (beta GRPs).}, keywords = {Animals, Carrier Proteins/chemistry/immunology/physiology, Cell Surface/immunology/*physiology, Drosophila Proteins/chemistry/immunology/*physiology, Drosophila/genetics/*immunology/microbiology, ferrandon, Fungi/immunology, Gene Expression Regulation, Gram-Negative Bacterial Infections/immunology, Gram-Positive Bacterial Infections/immunology, hoffmann, imler, Immunological, Insect Proteins/chemistry/immunology/physiology, M3i, Models, Non-U.S. Gov't, Receptors, Signal Transduction/immunology/physiology, Support}, pubstate = {published}, tppubtype = {article} } Drosophila has evolved a potent immune system that is somewhat adapted to the nature of infections through the selective activation of either one of two NF-kappa B-like signalling pathways, the Toll and IMD (Immune deficiency) pathways. In contrast to the mammalian system, the Toll receptor does not act as a pattern recognition receptor (PRR) but as a cytokine receptor. The sensing of microbial infections is achieved by at least four PRRs that belong to two distinct families: the peptidoglycan recognition proteins (PGRPs) and the Gram-negative binding proteins (GNBPs)/beta-glucan recognition proteins (beta GRPs). |
Imler, Jean-Luc; Zheng, Liangbiao Biology of Toll receptors: lessons from insects and mammals Article de journal Journal of Leukocyte Biology, 75 (1), p. 18–26, 2004, ISSN: 0741-5400. Résumé | Liens | BibTeX | Étiquettes: Animals, Anopheles, Cell Surface, Humans, imler, M3i, Membrane Glycoproteins, Mice, Phylogeny, Plant Physiological Phenomena, Receptors, Signal Transduction, Toll-Like Receptor 5, Toll-Like Receptors @article{imler_biology_2004, title = {Biology of Toll receptors: lessons from insects and mammals}, author = {Jean-Luc Imler and Liangbiao Zheng}, doi = {10.1189/jlb.0403160}, issn = {0741-5400}, year = {2004}, date = {2004-01-01}, journal = {Journal of Leukocyte Biology}, volume = {75}, number = {1}, pages = {18--26}, abstract = {Toll receptors are type I transmembrane proteins that play important roles in development and immunity in animals. Comparison of the genomes of mouse and human on one side and of the fruitfly Drosophila and the mosquito Anopheles (two dipteran insects) on the other, revealed that the four species possess a similar number of Toll receptors (approximately 10). However, phylogenetic analyses indicate that the families of Toll receptors expanded independently in insects and mammals. We review recent results on these receptors, which point to differences in the activation and signaling between Tolls in insects and Toll-like receptors (TLRs) in mammals. Whereas mammalian TLRs appear to be solely dedicated to host-defense, insect Tolls may be predominantly linked to other functions, probably developmental.}, keywords = {Animals, Anopheles, Cell Surface, Humans, imler, M3i, Membrane Glycoproteins, Mice, Phylogeny, Plant Physiological Phenomena, Receptors, Signal Transduction, Toll-Like Receptor 5, Toll-Like Receptors}, pubstate = {published}, tppubtype = {article} } Toll receptors are type I transmembrane proteins that play important roles in development and immunity in animals. Comparison of the genomes of mouse and human on one side and of the fruitfly Drosophila and the mosquito Anopheles (two dipteran insects) on the other, revealed that the four species possess a similar number of Toll receptors (approximately 10). However, phylogenetic analyses indicate that the families of Toll receptors expanded independently in insects and mammals. We review recent results on these receptors, which point to differences in the activation and signaling between Tolls in insects and Toll-like receptors (TLRs) in mammals. Whereas mammalian TLRs appear to be solely dedicated to host-defense, insect Tolls may be predominantly linked to other functions, probably developmental. |
Imler, Jean-Luc; Ferrandon, Dominique; Royet, Julien; Reichhart, Jean-Marc; Hetru, Charles; Hoffmann, Jules A Toll-dependent and Toll-independent immune responses in Drosophila Article de journal Journal of Endotoxin Research, 10 (4), p. 241–246, 2004, ISSN: 0968-0519. Résumé | Liens | BibTeX | Étiquettes: Acute-Phase Proteins, Animals, Blood Proteins, Cell Surface, ferrandon, hoffmann, imler, Insect Proteins, M3i, Membrane Glycoproteins, Receptors, reichhart, Toll-Like Receptor 5, Toll-Like Receptors, Up-Regulation @article{imler_toll-dependent_2004, title = {Toll-dependent and Toll-independent immune responses in Drosophila}, author = {Jean-Luc Imler and Dominique Ferrandon and Julien Royet and Jean-Marc Reichhart and Charles Hetru and Jules A Hoffmann}, doi = {10.1179/096805104225005887}, issn = {0968-0519}, year = {2004}, date = {2004-01-01}, journal = {Journal of Endotoxin Research}, volume = {10}, number = {4}, pages = {241--246}, abstract = {The multifaceted response of the fruitfly Drosophila melanogaster to infection by a wide range of microbes is complex and remarkably efficient. Its most prominent aspect is the immune-inducible expression of a set of potent antimicrobial peptides. Genetic analysis of the regulation of the genes encoding these peptides has led to the identification of the receptor Toll as an essential component of the fly's host defense system. In addition, these studies have revealed that the response to Gram-negative bacterial infections involves Toll-independent mechanisms, and that the sensing of infection involves two structurally distinct sets of molecules--the PGRPs and the GNBPs/betaGRPs.}, keywords = {Acute-Phase Proteins, Animals, Blood Proteins, Cell Surface, ferrandon, hoffmann, imler, Insect Proteins, M3i, Membrane Glycoproteins, Receptors, reichhart, Toll-Like Receptor 5, Toll-Like Receptors, Up-Regulation}, pubstate = {published}, tppubtype = {article} } The multifaceted response of the fruitfly Drosophila melanogaster to infection by a wide range of microbes is complex and remarkably efficient. Its most prominent aspect is the immune-inducible expression of a set of potent antimicrobial peptides. Genetic analysis of the regulation of the genes encoding these peptides has led to the identification of the receptor Toll as an essential component of the fly's host defense system. In addition, these studies have revealed that the response to Gram-negative bacterial infections involves Toll-independent mechanisms, and that the sensing of infection involves two structurally distinct sets of molecules--the PGRPs and the GNBPs/betaGRPs. |
2003 |
Ligoxygakis, Petros; Roth, Siegfried; Reichhart, Jean-Marc A serpin regulates dorsal-ventral axis formation in the Drosophila embryo Article de journal Curr. Biol., 13 (23), p. 2097–2102, 2003, ISSN: 0960-9822. Résumé | BibTeX | Étiquettes: Animals, Body Patterning, Cell Surface, Crosses, Female, Genetic, Immunohistochemistry, M3i, Microinjections, Receptors, reichhart, Serine Proteinase Inhibitors, Serpins, Signal Transduction, Toll-Like Receptors @article{ligoxygakis_serpin_2003, title = {A serpin regulates dorsal-ventral axis formation in the Drosophila embryo}, author = {Petros Ligoxygakis and Siegfried Roth and Jean-Marc Reichhart}, issn = {0960-9822}, year = {2003}, date = {2003-12-01}, journal = {Curr. Biol.}, volume = {13}, number = {23}, pages = {2097--2102}, abstract = {Extracellular serine protease cascades have evolved in vertebrates and invertebrates to mediate rapid, local reactions to physiological or pathological cues. The serine protease cascade that triggers the Toll signaling pathway in Drosophila embryogenesis shares several organizational characteristics with those involved in mammalian complement and blood clotting. One of the hallmarks of such cascades is their regulation by serine protease inhibitors (serpins). Serpins act as suicide substrates and are cleaved by their target protease, forming an essentially irreversible 1:1 complex. The biological importance of serpins is highlighted by serpin dysfunction diseases, such as thrombosis caused by a deficiency in antithrombin. Here, we describe how a serpin controls the serine protease cascade, leading to Toll pathway activation. Female flies deficient in Serpin-27A produce embryos that lack dorsal-ventral polarity and show uniform high levels of Toll signaling. Since this serpin has been recently shown to restrain an immune reaction in the blood of Drosophila, it demonstrates that proteolysis can be regulated by the same serpin in different biological contexts.}, keywords = {Animals, Body Patterning, Cell Surface, Crosses, Female, Genetic, Immunohistochemistry, M3i, Microinjections, Receptors, reichhart, Serine Proteinase Inhibitors, Serpins, Signal Transduction, Toll-Like Receptors}, pubstate = {published}, tppubtype = {article} } Extracellular serine protease cascades have evolved in vertebrates and invertebrates to mediate rapid, local reactions to physiological or pathological cues. The serine protease cascade that triggers the Toll signaling pathway in Drosophila embryogenesis shares several organizational characteristics with those involved in mammalian complement and blood clotting. One of the hallmarks of such cascades is their regulation by serine protease inhibitors (serpins). Serpins act as suicide substrates and are cleaved by their target protease, forming an essentially irreversible 1:1 complex. The biological importance of serpins is highlighted by serpin dysfunction diseases, such as thrombosis caused by a deficiency in antithrombin. Here, we describe how a serpin controls the serine protease cascade, leading to Toll pathway activation. Female flies deficient in Serpin-27A produce embryos that lack dorsal-ventral polarity and show uniform high levels of Toll signaling. Since this serpin has been recently shown to restrain an immune reaction in the blood of Drosophila, it demonstrates that proteolysis can be regulated by the same serpin in different biological contexts. |
Reichhart, Jean-Marc TLR5 takes aim at bacterial propeller Article de journal Nat. Immunol., 4 (12), p. 1159–1160, 2003, ISSN: 1529-2908. Liens | BibTeX | Étiquettes: Animals, Bacterial Physiological Phenomena, Cell Surface, Flagella, Flagellin, Humans, M3i, Membrane Glycoproteins, Receptors, reichhart, Toll-Like Receptor 5, Toll-Like Receptors @article{reichhart_tlr5_2003, title = {TLR5 takes aim at bacterial propeller}, author = {Jean-Marc Reichhart}, doi = {10.1038/ni1203-1159}, issn = {1529-2908}, year = {2003}, date = {2003-12-01}, journal = {Nat. Immunol.}, volume = {4}, number = {12}, pages = {1159--1160}, keywords = {Animals, Bacterial Physiological Phenomena, Cell Surface, Flagella, Flagellin, Humans, M3i, Membrane Glycoproteins, Receptors, reichhart, Toll-Like Receptor 5, Toll-Like Receptors}, pubstate = {published}, tppubtype = {article} } |
Royet, Julien; Reichhart, Jean-Marc Detection of peptidoglycans by NOD proteins Article de journal Trends Cell Biol., 13 (12), p. 610–614, 2003, ISSN: 0962-8924. Résumé | BibTeX | Étiquettes: Adaptor Proteins, Apoptosis, Carrier Proteins, Gram-Positive Bacteria, Humans, Immunity, Immunologic, Innate, M3i, Nod1 Signaling Adaptor Protein, Oligopeptides, peptidoglycan, Receptors, reichhart, Signal Transducing, Signal Transduction @article{royet_detection_2003, title = {Detection of peptidoglycans by NOD proteins}, author = {Julien Royet and Jean-Marc Reichhart}, issn = {0962-8924}, year = {2003}, date = {2003-12-01}, journal = {Trends Cell Biol.}, volume = {13}, number = {12}, pages = {610--614}, abstract = {Mechanisms of innate immune defense are based on the recognition of invariant microbial molecular patterns by specific receptors, followed by the activation of signaling pathways and the expression of effector molecules that will defeat the invading microorganism. Two recent reports add to the growing list of these pattern-recognition receptors by showing that the intracellular nucleotide-binding oligomerization domain 1 (NOD1) protein recognizes a diaminopimelate-containing muropeptide, a cell-wall component of Gram-negative bacteria.}, keywords = {Adaptor Proteins, Apoptosis, Carrier Proteins, Gram-Positive Bacteria, Humans, Immunity, Immunologic, Innate, M3i, Nod1 Signaling Adaptor Protein, Oligopeptides, peptidoglycan, Receptors, reichhart, Signal Transducing, Signal Transduction}, pubstate = {published}, tppubtype = {article} } Mechanisms of innate immune defense are based on the recognition of invariant microbial molecular patterns by specific receptors, followed by the activation of signaling pathways and the expression of effector molecules that will defeat the invading microorganism. Two recent reports add to the growing list of these pattern-recognition receptors by showing that the intracellular nucleotide-binding oligomerization domain 1 (NOD1) protein recognizes a diaminopimelate-containing muropeptide, a cell-wall component of Gram-negative bacteria. |
Gobert, Vanessa; Gottar, Marie; Matskevich, Alexey A; Rutschmann, Sophie; Royet, Julien; Belvin, Marcia; Hoffmann, Jules A; Ferrandon, Dominique Dual activation of the Drosophila toll pathway by two pattern recognition receptors Article de journal Science, 302 (5653), p. 2126–2130, 2003, ISSN: 1095-9203. Résumé | Liens | BibTeX | Étiquettes: Animals, Carrier Proteins, Cell Surface, DNA Transposable Elements, ferrandon, Gene Expression, Genes, Gram-Negative Bacteria, Gram-Positive Bacteria, Hemolymph, hoffmann, Hypocreales, Insect, Insect Proteins, M3i, Mutation, Phenotype, Receptors, Serine Endopeptidases, Toll-Like Receptors @article{gobert_dual_2003, title = {Dual activation of the Drosophila toll pathway by two pattern recognition receptors}, author = {Vanessa Gobert and Marie Gottar and Alexey A Matskevich and Sophie Rutschmann and Julien Royet and Marcia Belvin and Jules A Hoffmann and Dominique Ferrandon}, doi = {10.1126/science.1085432}, issn = {1095-9203}, year = {2003}, date = {2003-12-01}, journal = {Science}, volume = {302}, number = {5653}, pages = {2126--2130}, abstract = {The Toll-dependent defense against Gram-positive bacterial infections in Drosophila is mediated through the peptidoglycan recognition protein SA (PGRP-SA). A mutation termed osiris disrupts the Gram-negative binding protein 1 (GNBP1) gene and leads to compromised survival of mutant flies after Gram-positive infections, but not after fungal or Gram-negative bacterial challenge. Our results demonstrate that GNBP1 and PGRP-SA can jointly activate the Toll pathway. The potential for a combination of distinct proteins to mediate detection of infectious nonself in the fly will refine the concept of pattern recognition in insects.}, keywords = {Animals, Carrier Proteins, Cell Surface, DNA Transposable Elements, ferrandon, Gene Expression, Genes, Gram-Negative Bacteria, Gram-Positive Bacteria, Hemolymph, hoffmann, Hypocreales, Insect, Insect Proteins, M3i, Mutation, Phenotype, Receptors, Serine Endopeptidases, Toll-Like Receptors}, pubstate = {published}, tppubtype = {article} } The Toll-dependent defense against Gram-positive bacterial infections in Drosophila is mediated through the peptidoglycan recognition protein SA (PGRP-SA). A mutation termed osiris disrupts the Gram-negative binding protein 1 (GNBP1) gene and leads to compromised survival of mutant flies after Gram-positive infections, but not after fungal or Gram-negative bacterial challenge. Our results demonstrate that GNBP1 and PGRP-SA can jointly activate the Toll pathway. The potential for a combination of distinct proteins to mediate detection of infectious nonself in the fly will refine the concept of pattern recognition in insects. |
Goto, Akira; Blandin, Stéphanie A; Royet, Julien; Reichhart, Jean-Marc; Levashina, Elena A Silencing of Toll pathway components by direct injection of double-stranded RNA into Drosophila adult flies Article de journal Nucleic Acids Res., 31 (22), p. 6619–6623, 2003, ISSN: 1362-4962. Résumé | BibTeX | Étiquettes: Animals, blandin, Cell Surface, Double-Stranded, Epistasis, Female, Genetic, Green Fluorescent Proteins, Homeodomain Proteins, Luminescent Proteins, M3i, Phenotype, Receptors, reichhart, RNA, RNA Interference, Serpins, Signal Transduction, Time Factors, Toll-Like Receptors, Transcription Factors @article{goto_silencing_2003, title = {Silencing of Toll pathway components by direct injection of double-stranded RNA into Drosophila adult flies}, author = {Akira Goto and Stéphanie A Blandin and Julien Royet and Jean-Marc Reichhart and Elena A Levashina}, issn = {1362-4962}, year = {2003}, date = {2003-11-01}, journal = {Nucleic Acids Res.}, volume = {31}, number = {22}, pages = {6619--6623}, abstract = {Double-stranded RNA (dsRNA) gene interference is an efficient method to silence gene expression in a sequence-specific manner. Here we show that the direct injection of dsRNA can be used in adult Drosophila flies to disrupt function of endogenous genes in vivo. As a proof of principle, we have used this method to silence components of a major signaling cascade, the Toll pathway, which controls fruit fly resistance to fungal and Gram-positive bacterial infections. We demonstrate that the knockout is efficient only if dsRNA is injected in 4- or more day-old flies and that it lasts for at least 1 week. Furthermore, we report dsRNA-based epistatic gene analysis via injection of a mixture of two dsRNAs and propose that injection of dsRNA represents a powerful method for rapid functional analysis of genes in Drosophila melanogaster adults, particularly of those whose mutations are lethal during development.}, keywords = {Animals, blandin, Cell Surface, Double-Stranded, Epistasis, Female, Genetic, Green Fluorescent Proteins, Homeodomain Proteins, Luminescent Proteins, M3i, Phenotype, Receptors, reichhart, RNA, RNA Interference, Serpins, Signal Transduction, Time Factors, Toll-Like Receptors, Transcription Factors}, pubstate = {published}, tppubtype = {article} } Double-stranded RNA (dsRNA) gene interference is an efficient method to silence gene expression in a sequence-specific manner. Here we show that the direct injection of dsRNA can be used in adult Drosophila flies to disrupt function of endogenous genes in vivo. As a proof of principle, we have used this method to silence components of a major signaling cascade, the Toll pathway, which controls fruit fly resistance to fungal and Gram-positive bacterial infections. We demonstrate that the knockout is efficient only if dsRNA is injected in 4- or more day-old flies and that it lasts for at least 1 week. Furthermore, we report dsRNA-based epistatic gene analysis via injection of a mixture of two dsRNAs and propose that injection of dsRNA represents a powerful method for rapid functional analysis of genes in Drosophila melanogaster adults, particularly of those whose mutations are lethal during development. |
Hoffmann, Jules A The immune response of Drosophila Article de journal Nature, 426 (6962), p. 33–38, 2003, ISSN: 1476-4687. Résumé | Liens | BibTeX | Étiquettes: Animals, Cell Surface, hoffmann, Immunity, Innate, M3i, Membrane Glycoproteins, Receptors, Signal Transduction, Toll-Like Receptor 5, Toll-Like Receptors @article{hoffmann_immune_2003, title = {The immune response of Drosophila}, author = {Jules A Hoffmann}, doi = {10.1038/nature02021}, issn = {1476-4687}, year = {2003}, date = {2003-11-01}, journal = {Nature}, volume = {426}, number = {6962}, pages = {33--38}, abstract = {Drosophila mounts a potent host defence when challenged by various microorganisms. Analysis of this defence by molecular genetics has now provided a global picture of the mechanisms by which this insect senses infection, discriminates between various classes of microorganisms and induces the production of effector molecules, among which antimicrobial peptides are prominent. An unexpected result of these studies was the discovery that most of the genes involved in the Drosophila host defence are homologous or very similar to genes implicated in mammalian innate immune defences. Recent progress in research on Drosophila immune defence provides evidence for similarities and differences between Drosophila immune responses and mammalian innate immunity.}, keywords = {Animals, Cell Surface, hoffmann, Immunity, Innate, M3i, Membrane Glycoproteins, Receptors, Signal Transduction, Toll-Like Receptor 5, Toll-Like Receptors}, pubstate = {published}, tppubtype = {article} } Drosophila mounts a potent host defence when challenged by various microorganisms. Analysis of this defence by molecular genetics has now provided a global picture of the mechanisms by which this insect senses infection, discriminates between various classes of microorganisms and induces the production of effector molecules, among which antimicrobial peptides are prominent. An unexpected result of these studies was the discovery that most of the genes involved in the Drosophila host defence are homologous or very similar to genes implicated in mammalian innate immune defences. Recent progress in research on Drosophila immune defence provides evidence for similarities and differences between Drosophila immune responses and mammalian innate immunity. |
Weber, Alexander N R; Tauszig-Delamasure, Servane; Hoffmann, Jules A; Lelièvre, Eric; Gascan, Hugues; Ray, Keith P; Morse, Mary A; Imler, Jean-Luc; Gay, Nicholas J Binding of the Drosophila cytokine Spätzle to Toll is direct and establishes signaling Article de journal Nature Immunology, 4 (8), p. 794–800, 2003, ISSN: 1529-2908. Résumé | Liens | BibTeX | Étiquettes: Animals, Cell Surface, hoffmann, imler, Insect Proteins, M3i, Protein Binding, Protein Structure, Receptors, Signal Transduction, Tertiary, Toll-Like Receptors @article{weber_binding_2003, title = {Binding of the Drosophila cytokine Spätzle to Toll is direct and establishes signaling}, author = {Alexander N R Weber and Servane Tauszig-Delamasure and Jules A Hoffmann and Eric Lelièvre and Hugues Gascan and Keith P Ray and Mary A Morse and Jean-Luc Imler and Nicholas J Gay}, doi = {10.1038/ni955}, issn = {1529-2908}, year = {2003}, date = {2003-08-01}, journal = {Nature Immunology}, volume = {4}, number = {8}, pages = {794--800}, abstract = {The extracellular protein Spätzle is required for activation of the Toll signaling pathway in the embryonic development and innate immune defense of Drosophila. Spätzle is synthesized as a pro-protein and is processed to a functional form by a serine protease. We show here that the mature form of Spätzle triggers a Toll-dependent immune response after injection into the hemolymph of flies. Spätzle specifically bound to Drosophila cells and to Cos-7 cells expressing Toll. Furthermore, in vitro experiments showed that the mature form of Spätzle bound to the Toll ectodomain with high affinity and with a stoichiometry of one Spätzle dimer to two receptors. The Spätzle pro-protein was inactive in all these assays, indicating that the pro-domain sequence, which is natively unstructured, acts to prevent interaction of the cytokine and its receptor Toll. These results show that, in contrast to the human Toll-like receptors, Drosophila Toll requires only an endogenous protein ligand for activation and signaling.}, keywords = {Animals, Cell Surface, hoffmann, imler, Insect Proteins, M3i, Protein Binding, Protein Structure, Receptors, Signal Transduction, Tertiary, Toll-Like Receptors}, pubstate = {published}, tppubtype = {article} } The extracellular protein Spätzle is required for activation of the Toll signaling pathway in the embryonic development and innate immune defense of Drosophila. Spätzle is synthesized as a pro-protein and is processed to a functional form by a serine protease. We show here that the mature form of Spätzle triggers a Toll-dependent immune response after injection into the hemolymph of flies. Spätzle specifically bound to Drosophila cells and to Cos-7 cells expressing Toll. Furthermore, in vitro experiments showed that the mature form of Spätzle bound to the Toll ectodomain with high affinity and with a stoichiometry of one Spätzle dimer to two receptors. The Spätzle pro-protein was inactive in all these assays, indicating that the pro-domain sequence, which is natively unstructured, acts to prevent interaction of the cytokine and its receptor Toll. These results show that, in contrast to the human Toll-like receptors, Drosophila Toll requires only an endogenous protein ligand for activation and signaling. |
Bilak, Hana; Tauszig-Delamasure, S; Imler, Jean-Luc Toll and Toll-like receptors in Drosophila Article de journal Biochemical Society Transactions, 31 (Pt 3), p. 648–651, 2003, ISSN: 0300-5127. Résumé | Liens | BibTeX | Étiquettes: Animals, Biological Evolution, Cell Surface, Fungi, Genome, Gram-Negative Bacteria, Gram-Positive Bacteria, imler, M3i, Membrane Glycoproteins, Receptors, Toll-Like Receptor 5, Toll-Like Receptors @article{bilak_toll_2003, title = {Toll and Toll-like receptors in Drosophila}, author = {Hana Bilak and S Tauszig-Delamasure and Jean-Luc Imler}, doi = {10.1042/}, issn = {0300-5127}, year = {2003}, date = {2003-06-01}, journal = {Biochemical Society Transactions}, volume = {31}, number = {Pt 3}, pages = {648--651}, abstract = {The Drosophila Toll receptor controls the immune response to Gram-positive bacteria and fungi by activating a signalling pathway partially conserved throughout evolution. The Drosophila genome encodes eight additional Toll-related receptors, most of which appear to carry out developmental rather than immune functions. One exception may be Toll-9, which shares structural and functional similarities with mammalian TLRs.}, keywords = {Animals, Biological Evolution, Cell Surface, Fungi, Genome, Gram-Negative Bacteria, Gram-Positive Bacteria, imler, M3i, Membrane Glycoproteins, Receptors, Toll-Like Receptor 5, Toll-Like Receptors}, pubstate = {published}, tppubtype = {article} } The Drosophila Toll receptor controls the immune response to Gram-positive bacteria and fungi by activating a signalling pathway partially conserved throughout evolution. The Drosophila genome encodes eight additional Toll-related receptors, most of which appear to carry out developmental rather than immune functions. One exception may be Toll-9, which shares structural and functional similarities with mammalian TLRs. |
Luna, C; Hoa, N T; Zhang, J; Kanzok, S M; Brown, S E; Imler, Jean-Luc; Knudson, D L; Zheng, L Characterization of three Toll-like genes from mosquito Aedes aegypti Article de journal Insect Molecular Biology, 12 (1), p. 67–74, 2003, ISSN: 0962-1075. Résumé | BibTeX | Étiquettes: Aedes, Animals, Base Sequence, Cell Surface, Chimera, Cloning, Developmental, Female, Gene Expression Regulation, Genetic, imler, Insect Proteins, M3i, Male, messenger, Models, Molecular, Mutagenesis, Promoter Regions, Receptors, Reverse Transcriptase Polymerase Chain Reaction, RNA, Sequence Alignment, Signal Transduction, Site-Directed, Transfection @article{luna_characterization_2003, title = {Characterization of three Toll-like genes from mosquito Aedes aegypti}, author = {C Luna and N T Hoa and J Zhang and S M Kanzok and S E Brown and Jean-Luc Imler and D L Knudson and L Zheng}, issn = {0962-1075}, year = {2003}, date = {2003-02-01}, journal = {Insect Molecular Biology}, volume = {12}, number = {1}, pages = {67--74}, abstract = {Three Toll-related genes (AeToll1A, AeToll1B and AeToll5) were cloned and characterized from the yellow fever vector mosquito, Aedes aegypti. All three genes exhibited high levels of amino acid sequence similarity with Drosophila melanogaster (Dm)Toll1 and DmTehao (Toll5). AeToll1A and AeToll1B are 1124 and 1076 amino acid residues long, respectively. Both contain a carboxyl extension downstream of the Toll/interleukin-1 receptor (TIR) domain. AeToll5 is 1007 residues long and, like DmTehao, lacks the carboxyl terminal extension. Expression of these three genes was examined throughout development and after immune challenge. Both AeToll1A and AeToll5, like their Drosophila counterparts, activate transcription of drosomycin promoter in both Aedes and Drosophila cell lines. Deletion of the carboxyl extension of AeToll1A did not result in a further elevated level of the antifungal response. The intracellular signalling process appears to be species specific based on two observations. (1) DmToll is completely inactive in an Aedes cell line, suggesting a higher specificity requirement for DmToll in the intracellular signalling process. (2) Only one of three amino acid residues essential for DmToll function is required for AeToll1A function.}, keywords = {Aedes, Animals, Base Sequence, Cell Surface, Chimera, Cloning, Developmental, Female, Gene Expression Regulation, Genetic, imler, Insect Proteins, M3i, Male, messenger, Models, Molecular, Mutagenesis, Promoter Regions, Receptors, Reverse Transcriptase Polymerase Chain Reaction, RNA, Sequence Alignment, Signal Transduction, Site-Directed, Transfection}, pubstate = {published}, tppubtype = {article} } Three Toll-related genes (AeToll1A, AeToll1B and AeToll5) were cloned and characterized from the yellow fever vector mosquito, Aedes aegypti. All three genes exhibited high levels of amino acid sequence similarity with Drosophila melanogaster (Dm)Toll1 and DmTehao (Toll5). AeToll1A and AeToll1B are 1124 and 1076 amino acid residues long, respectively. Both contain a carboxyl extension downstream of the Toll/interleukin-1 receptor (TIR) domain. AeToll5 is 1007 residues long and, like DmTehao, lacks the carboxyl terminal extension. Expression of these three genes was examined throughout development and after immune challenge. Both AeToll1A and AeToll5, like their Drosophila counterparts, activate transcription of drosomycin promoter in both Aedes and Drosophila cell lines. Deletion of the carboxyl extension of AeToll1A did not result in a further elevated level of the antifungal response. The intracellular signalling process appears to be species specific based on two observations. (1) DmToll is completely inactive in an Aedes cell line, suggesting a higher specificity requirement for DmToll in the intracellular signalling process. (2) Only one of three amino acid residues essential for DmToll function is required for AeToll1A function. |
Imler, Jean-Luc; Hoffmann, Jules A Toll signaling: the TIReless quest for specificity Article de journal Nature Immunology, 4 (2), p. 105–106, 2003, ISSN: 1529-2908. Liens | BibTeX | Étiquettes: Animals, Cell Surface, Dendritic Cells, hoffmann, Humans, imler, Immunological, Interferon-beta, M3i, Membrane Glycoproteins, Mice, Models, Protein Structure, Receptors, Signal Transduction, Tertiary, Toll-Like Receptors @article{imler_toll_2003, title = {Toll signaling: the TIReless quest for specificity}, author = {Jean-Luc Imler and Jules A Hoffmann}, doi = {10.1038/ni0203-105}, issn = {1529-2908}, year = {2003}, date = {2003-02-01}, journal = {Nature Immunology}, volume = {4}, number = {2}, pages = {105--106}, keywords = {Animals, Cell Surface, Dendritic Cells, hoffmann, Humans, imler, Immunological, Interferon-beta, M3i, Membrane Glycoproteins, Mice, Models, Protein Structure, Receptors, Signal Transduction, Tertiary, Toll-Like Receptors}, pubstate = {published}, tppubtype = {article} } |
Kambris, Zakaria; Bilak, Hana; D'Alessandro, Rosalba; Belvin, Marcia; Imler, Jean-Luc; Capovilla, Maria DmMyD88 controls dorsoventral patterning of the Drosophila embryo Article de journal EMBO reports, 4 (1), p. 64–69, 2003, ISSN: 1469-221X. Résumé | Liens | BibTeX | Étiquettes: Adaptor Proteins, Alleles, Animals, Antigens, Base Sequence, Cell Surface, Complementary, Developmental, Differentiation, DNA, DNA Transposable Elements, Egg Proteins, Embryo, Exons, Female, Gene Expression Regulation, Genetically Modified, Genotype, imler, Immunity, Immunologic, Innate, Insertional, M3i, Male, messenger, Morphogenesis, Mutagenesis, Myeloid Differentiation Factor 88, Nonmammalian, Oocytes, Protein Biosynthesis, Protein Structure, Receptors, Reverse Transcriptase Polymerase Chain Reaction, RNA, Signal Transducing, Tertiary, Toll-Like Receptors, Zygote @article{kambris_dmmyd88_2003, title = {DmMyD88 controls dorsoventral patterning of the Drosophila embryo}, author = {Zakaria Kambris and Hana Bilak and Rosalba D'Alessandro and Marcia Belvin and Jean-Luc Imler and Maria Capovilla}, doi = {10.1038/sj.embor.embor714}, issn = {1469-221X}, year = {2003}, date = {2003-01-01}, journal = {EMBO reports}, volume = {4}, number = {1}, pages = {64--69}, abstract = {MyD88 is an adapter protein in the signal transduction pathway mediated by interleukin-1 (IL-1) and Toll-like receptors. A Drosophila homologue of MyD88 (DmMyD88) was recently shown to be required for the Toll-mediated immune response. In Drosophila, the Toll pathway was originally characterized for its role in the dorsoventral patterning of the embryo. We found that, like Toll, DmMyD88 messenger RNA is maternally supplied to the embryo. Here we report the identification of a new mutant allele of DmMyD88, which generates a protein lacking the carboxy-terminal extension, normally located downstream of the Toll/IL-1 receptor domain. Homozygous mutant female flies lay dorsalized embryos that are rescued by expression of a transgenic DmMyD88 complementary DNA. The DmMyD88 mutation blocks the ventralizing activity of a gain-of-function Toll mutation. These results show that DmMyD88 encodes an essential component of the Toll pathway in dorsoventral pattern formation.}, keywords = {Adaptor Proteins, Alleles, Animals, Antigens, Base Sequence, Cell Surface, Complementary, Developmental, Differentiation, DNA, DNA Transposable Elements, Egg Proteins, Embryo, Exons, Female, Gene Expression Regulation, Genetically Modified, Genotype, imler, Immunity, Immunologic, Innate, Insertional, M3i, Male, messenger, Morphogenesis, Mutagenesis, Myeloid Differentiation Factor 88, Nonmammalian, Oocytes, Protein Biosynthesis, Protein Structure, Receptors, Reverse Transcriptase Polymerase Chain Reaction, RNA, Signal Transducing, Tertiary, Toll-Like Receptors, Zygote}, pubstate = {published}, tppubtype = {article} } MyD88 is an adapter protein in the signal transduction pathway mediated by interleukin-1 (IL-1) and Toll-like receptors. A Drosophila homologue of MyD88 (DmMyD88) was recently shown to be required for the Toll-mediated immune response. In Drosophila, the Toll pathway was originally characterized for its role in the dorsoventral patterning of the embryo. We found that, like Toll, DmMyD88 messenger RNA is maternally supplied to the embryo. Here we report the identification of a new mutant allele of DmMyD88, which generates a protein lacking the carboxy-terminal extension, normally located downstream of the Toll/IL-1 receptor domain. Homozygous mutant female flies lay dorsalized embryos that are rescued by expression of a transgenic DmMyD88 complementary DNA. The DmMyD88 mutation blocks the ventralizing activity of a gain-of-function Toll mutation. These results show that DmMyD88 encodes an essential component of the Toll pathway in dorsoventral pattern formation. |
2002 |
Ligoxygakis, Petros; Pelte, Nadège; Ji, Chuanyi; Leclerc, Vincent; Duvic, Bernard; Belvin, Marcia; Jiang, Haobo; Hoffmann, Jules A; Reichhart, Jean-Marc A serpin mutant links Toll activation to melanization in the host defence of Drosophila Article de journal EMBO J., 21 (23), p. 6330–6337, 2002, ISSN: 0261-4189. Résumé | BibTeX | Étiquettes: Animals, Cell Surface, Hemolymph, hoffmann, infection, M3i, Melanins, Receptors, reichhart, Serpins, Toll-Like Receptors @article{ligoxygakis_serpin_2002, title = {A serpin mutant links Toll activation to melanization in the host defence of Drosophila}, author = {Petros Ligoxygakis and Nadège Pelte and Chuanyi Ji and Vincent Leclerc and Bernard Duvic and Marcia Belvin and Haobo Jiang and Jules A Hoffmann and Jean-Marc Reichhart}, issn = {0261-4189}, year = {2002}, date = {2002-12-01}, journal = {EMBO J.}, volume = {21}, number = {23}, pages = {6330--6337}, abstract = {A prominent response during the Drosophila host defence is the induction of proteolytic cascades, some of which lead to localized melanization of pathogen surfaces, while others activate one of the major players in the systemic antimicrobial response, the Toll pathway. Despite the fact that gain-of-function mutations in the Toll receptor gene result in melanization, a clear link between Toll activation and the melanization reaction has not been firmly established. Here, we present evidence for the coordination of hemolymph-borne melanization with activation of the Toll pathway in the Drosophila host defence. The melanization reaction requires Toll pathway activation and depends on the removal of the Drosophila serine protease inhibitor Serpin27A. Flies deficient for this serpin exhibit spontaneous melanization in larvae and adults. Microbial challenge induces its removal from the hemolymph through Toll-dependent transcription of an acute phase immune reaction component.}, keywords = {Animals, Cell Surface, Hemolymph, hoffmann, infection, M3i, Melanins, Receptors, reichhart, Serpins, Toll-Like Receptors}, pubstate = {published}, tppubtype = {article} } A prominent response during the Drosophila host defence is the induction of proteolytic cascades, some of which lead to localized melanization of pathogen surfaces, while others activate one of the major players in the systemic antimicrobial response, the Toll pathway. Despite the fact that gain-of-function mutations in the Toll receptor gene result in melanization, a clear link between Toll activation and the melanization reaction has not been firmly established. Here, we present evidence for the coordination of hemolymph-borne melanization with activation of the Toll pathway in the Drosophila host defence. The melanization reaction requires Toll pathway activation and depends on the removal of the Drosophila serine protease inhibitor Serpin27A. Flies deficient for this serpin exhibit spontaneous melanization in larvae and adults. Microbial challenge induces its removal from the hemolymph through Toll-dependent transcription of an acute phase immune reaction component. |
Munier, Anne-Isabelle; Doucet, Daniel; Perrodou, Emmanuel; Zachary, Daniel; Meister, Marie; Hoffmann, Jules A; Janeway, Charles A; Lagueux, Marie PVF2, a PDGF/VEGF-like growth factor, induces hemocyte proliferation in Drosophila larvae Article de journal EMBO Rep., 3 (12), p. 1195–1200, 2002, ISSN: 1469-221X. Résumé | Liens | BibTeX | Étiquettes: Animals, Antibodies, Blotting, Cell Differentiation, Hemocytes, hoffmann, Immunohistochemistry, Larva, ligands, M3i, Platelet-Derived Growth Factor, Receptors, Vascular Endothelial Growth Factor, Western @article{munier_pvf2_2002, title = {PVF2, a PDGF/VEGF-like growth factor, induces hemocyte proliferation in Drosophila larvae}, author = {Anne-Isabelle Munier and Daniel Doucet and Emmanuel Perrodou and Daniel Zachary and Marie Meister and Jules A Hoffmann and Charles A Janeway and Marie Lagueux}, doi = {10.1093/embo-reports/kvf242}, issn = {1469-221X}, year = {2002}, date = {2002-12-01}, journal = {EMBO Rep.}, volume = {3}, number = {12}, pages = {1195--1200}, abstract = {Blood cells play a crucial role in both morphogenetic and immunological processes in Drosophila, yet the factors regulating their proliferation remain largely unknown. In order to address this question, we raised antibodies against a tumorous blood cell line and identified an antigenic determinant that marks the surface of prohemocytes and also circulating plasmatocytes in larvae. This antigen was identified as a Drosophila homolog of the mammalian receptor for platelet-derived growth factor (PDGF)/vascular endothelial growth factor (VEGF). The Drosophila receptor controls cell proliferation in vitro. By overexpressing in vivo one of its putative ligands, PVF2, we induced a dramatic increase in circulating hemocytes. These results identify the PDGF/VEGF receptor homolog and one of its ligands as important players in Drosophila hematopoiesis.}, keywords = {Animals, Antibodies, Blotting, Cell Differentiation, Hemocytes, hoffmann, Immunohistochemistry, Larva, ligands, M3i, Platelet-Derived Growth Factor, Receptors, Vascular Endothelial Growth Factor, Western}, pubstate = {published}, tppubtype = {article} } Blood cells play a crucial role in both morphogenetic and immunological processes in Drosophila, yet the factors regulating their proliferation remain largely unknown. In order to address this question, we raised antibodies against a tumorous blood cell line and identified an antigenic determinant that marks the surface of prohemocytes and also circulating plasmatocytes in larvae. This antigen was identified as a Drosophila homolog of the mammalian receptor for platelet-derived growth factor (PDGF)/vascular endothelial growth factor (VEGF). The Drosophila receptor controls cell proliferation in vitro. By overexpressing in vivo one of its putative ligands, PVF2, we induced a dramatic increase in circulating hemocytes. These results identify the PDGF/VEGF receptor homolog and one of its ligands as important players in Drosophila hematopoiesis. |
Kambris, Zakaria; Hoffmann, Jules A; Imler, Jean-Luc; Capovilla, Maria Tissue and stage-specific expression of the Tolls in Drosophila embryos Article de journal Gene expression patterns: GEP, 2 (3-4), p. 311–317, 2002, ISSN: 1567-133X. Résumé | BibTeX | Étiquettes: Animals, Blotting, Cell Surface, Gene Expression Profiling, hoffmann, imler, Larva, M3i, Multigene Family, Northern, Receptors, Toll-Like Receptors @article{kambris_tissue_2002, title = {Tissue and stage-specific expression of the Tolls in Drosophila embryos}, author = {Zakaria Kambris and Jules A Hoffmann and Jean-Luc Imler and Maria Capovilla}, issn = {1567-133X}, year = {2002}, date = {2002-12-01}, journal = {Gene expression patterns: GEP}, volume = {2}, number = {3-4}, pages = {311--317}, abstract = {The Drosophila transmembrane receptor Toll plays a key role in specifying the dorsoventral axis of the embryo. At later stages of development, it controls the immune response of the fly to fungal and Gram-positive bacterial infections. The Drosophila genome has a total of nine Toll-like genes, including the previously characterized Toll (Toll-1) and 18-wheeler (Toll-2). Here we describe the embryonic expression patterns of the seven Toll-like genes Toll-3 through Toll-9. We find that these genes have distinct expression domains and that their expression is dynamically changing throughout embryonic development. This complex and tissue-specific regulation of Toll-like gene expression strongly suggests a role in embryonic development for most Drosophila Tolls. The evolving picture on the Toll family members in Drosophila contrasts with that of mammalian Toll-like receptors, which are predominantly expressed in immune responsive cells where their activation occurs via microbial structural determinants.}, keywords = {Animals, Blotting, Cell Surface, Gene Expression Profiling, hoffmann, imler, Larva, M3i, Multigene Family, Northern, Receptors, Toll-Like Receptors}, pubstate = {published}, tppubtype = {article} } The Drosophila transmembrane receptor Toll plays a key role in specifying the dorsoventral axis of the embryo. At later stages of development, it controls the immune response of the fly to fungal and Gram-positive bacterial infections. The Drosophila genome has a total of nine Toll-like genes, including the previously characterized Toll (Toll-1) and 18-wheeler (Toll-2). Here we describe the embryonic expression patterns of the seven Toll-like genes Toll-3 through Toll-9. We find that these genes have distinct expression domains and that their expression is dynamically changing throughout embryonic development. This complex and tissue-specific regulation of Toll-like gene expression strongly suggests a role in embryonic development for most Drosophila Tolls. The evolving picture on the Toll family members in Drosophila contrasts with that of mammalian Toll-like receptors, which are predominantly expressed in immune responsive cells where their activation occurs via microbial structural determinants. |
Duvic, Bernard; Hoffmann, Jules A; Meister, Marie; Royet, Julien Notch signaling controls lineage specification during Drosophila larval hematopoiesis Article de journal Curr. Biol., 12 (22), p. 1923–1927, 2002, ISSN: 0960-9822. Résumé | BibTeX | Étiquettes: Animals, Cell Differentiation, Hematopoiesis, hoffmann, Larva, Lymphoid Tissue, M3i, Membrane Proteins, Notch, Receptors, Signal Transduction @article{duvic_notch_2002, title = {Notch signaling controls lineage specification during Drosophila larval hematopoiesis}, author = {Bernard Duvic and Jules A Hoffmann and Marie Meister and Julien Royet}, issn = {0960-9822}, year = {2002}, date = {2002-11-01}, journal = {Curr. Biol.}, volume = {12}, number = {22}, pages = {1923--1927}, abstract = {Drosophila larval hemocytes originate from a hematopoietic organ called lymph glands, which are composed of paired lobes located along the dorsal vessel. Two mature blood cell populations are found in the circulating hemolymph: the macrophage-like plasmatocytes, and the crystal cells that contain enzymes of the immune-related melanization process. A third class of cells, called lamellocytes, are normally absent in larvae but differentiate after infection by parasites too large to be phagocytosed. Here we present evidence that the Notch signaling pathway plays an instructive role in the differentiation of crystal cells. Loss-of-function mutations in Notch result in severely decreased crystal cell numbers, whereas overexpression of Notch provokes the differentiation of high numbers of these cells. We demonstrate that, in this process, Serrate, not Delta, is the Notch ligand. In addition, Notch function is necessary for lamellocyte proliferation upon parasitization, although Notch overexpression does not result in lamellocyte production. Finally, Notch does not appear to play a role in the differentiation of the plasmatocyte lineage. This study underlines the existence of parallels in the genetic control of hematopoiesis in Drosophila and in mammals.}, keywords = {Animals, Cell Differentiation, Hematopoiesis, hoffmann, Larva, Lymphoid Tissue, M3i, Membrane Proteins, Notch, Receptors, Signal Transduction}, pubstate = {published}, tppubtype = {article} } Drosophila larval hemocytes originate from a hematopoietic organ called lymph glands, which are composed of paired lobes located along the dorsal vessel. Two mature blood cell populations are found in the circulating hemolymph: the macrophage-like plasmatocytes, and the crystal cells that contain enzymes of the immune-related melanization process. A third class of cells, called lamellocytes, are normally absent in larvae but differentiate after infection by parasites too large to be phagocytosed. Here we present evidence that the Notch signaling pathway plays an instructive role in the differentiation of crystal cells. Loss-of-function mutations in Notch result in severely decreased crystal cell numbers, whereas overexpression of Notch provokes the differentiation of high numbers of these cells. We demonstrate that, in this process, Serrate, not Delta, is the Notch ligand. In addition, Notch function is necessary for lamellocyte proliferation upon parasitization, although Notch overexpression does not result in lamellocyte production. Finally, Notch does not appear to play a role in the differentiation of the plasmatocyte lineage. This study underlines the existence of parallels in the genetic control of hematopoiesis in Drosophila and in mammals. |
Ligoxygakis, Petros; Pelte, Nadège; Hoffmann, Jules A; Reichhart, Jean-Marc Activation of Drosophila Toll during fungal infection by a blood serine protease Article de journal Science, 297 (5578), p. 114–116, 2002, ISSN: 1095-9203. Résumé | Liens | BibTeX | Étiquettes: Animals, Cell Surface, Chromosome Mapping, Escherichia coli, Female, Gene Expression Regulation, Genes, Gram-Positive Cocci, Hemolymph, hoffmann, Hypocreales, Insect, Insect Proteins, M3i, Male, Mutation, Protein Sorting Signals, Protein Structure, Receptors, reichhart, Serine Endopeptidases, Tertiary, Toll-Like Receptors @article{ligoxygakis_activation_2002, title = {Activation of Drosophila Toll during fungal infection by a blood serine protease}, author = {Petros Ligoxygakis and Nadège Pelte and Jules A Hoffmann and Jean-Marc Reichhart}, doi = {10.1126/science.1072391}, issn = {1095-9203}, year = {2002}, date = {2002-07-01}, journal = {Science}, volume = {297}, number = {5578}, pages = {114--116}, abstract = {Drosophila host defense to fungal and Gram-positive bacterial infection is mediated by the Spaetzle/Toll/cactus gene cassette. It has been proposed that Toll does not function as a pattern recognition receptor per se but is activated through a cleaved form of the cytokine Spaetzle. The upstream events linking infection to the cleavage of Spaetzle have long remained elusive. Here we report the identification of a central component of the fungal activation of Toll. We show that ethylmethane sulfonate-induced mutations in the persephone gene, which encodes a previously unknown serine protease, block induction of the Toll pathway by fungi and resistance to this type of infection.}, keywords = {Animals, Cell Surface, Chromosome Mapping, Escherichia coli, Female, Gene Expression Regulation, Genes, Gram-Positive Cocci, Hemolymph, hoffmann, Hypocreales, Insect, Insect Proteins, M3i, Male, Mutation, Protein Sorting Signals, Protein Structure, Receptors, reichhart, Serine Endopeptidases, Tertiary, Toll-Like Receptors}, pubstate = {published}, tppubtype = {article} } Drosophila host defense to fungal and Gram-positive bacterial infection is mediated by the Spaetzle/Toll/cactus gene cassette. It has been proposed that Toll does not function as a pattern recognition receptor per se but is activated through a cleaved form of the cytokine Spaetzle. The upstream events linking infection to the cleavage of Spaetzle have long remained elusive. Here we report the identification of a central component of the fungal activation of Toll. We show that ethylmethane sulfonate-induced mutations in the persephone gene, which encodes a previously unknown serine protease, block induction of the Toll pathway by fungi and resistance to this type of infection. |
Hoffmann, Jules A; Reichhart, Jean-Marc Drosophila innate immunity: an evolutionary perspective Article de journal Nat. Immunol., 3 (2), p. 121–126, 2002, ISSN: 1529-2908. Résumé | Liens | BibTeX | Étiquettes: Animals, Biological Evolution, Cell Surface, hoffmann, Immunity, Immunological, Innate, M3i, Membrane Glycoproteins, Models, Receptors, reichhart, Signal Transduction, Toll-Like Receptors @article{hoffmann_drosophila_2002, title = {Drosophila innate immunity: an evolutionary perspective}, author = {Jules A Hoffmann and Jean-Marc Reichhart}, doi = {10.1038/ni0202-121}, issn = {1529-2908}, year = {2002}, date = {2002-02-01}, journal = {Nat. Immunol.}, volume = {3}, number = {2}, pages = {121--126}, abstract = {In response to microbial infections, Drosophila mounts a multifaceted immune response involving humoral reactions that culminate in the destruction of invading organisms by lytic peptides. These defense mechanisms are activated via two distinct signaling pathways. One of these, the Toll pathway, controls resistance to fungal and Gram-positive bacterial infections, whereas the Imd pathway is responsible for defense against Gram-negative bacterial infections. Current evidence indicates that recognition of infectious nonself agents results from interactions between microbial wall components and extracellular pattern recognition proteins. We discuss here evolutionary perspectives on our present understanding of the antimicrobial defenses of Drosophila.}, keywords = {Animals, Biological Evolution, Cell Surface, hoffmann, Immunity, Immunological, Innate, M3i, Membrane Glycoproteins, Models, Receptors, reichhart, Signal Transduction, Toll-Like Receptors}, pubstate = {published}, tppubtype = {article} } In response to microbial infections, Drosophila mounts a multifaceted immune response involving humoral reactions that culminate in the destruction of invading organisms by lytic peptides. These defense mechanisms are activated via two distinct signaling pathways. One of these, the Toll pathway, controls resistance to fungal and Gram-positive bacterial infections, whereas the Imd pathway is responsible for defense against Gram-negative bacterial infections. Current evidence indicates that recognition of infectious nonself agents results from interactions between microbial wall components and extracellular pattern recognition proteins. We discuss here evolutionary perspectives on our present understanding of the antimicrobial defenses of Drosophila. |
Ligoxygakis, Petros; Bulet, Philippe; Reichhart, Jean-Marc Critical evaluation of the role of the Toll-like receptor 18-Wheeler in the host defense of Drosophila Article de journal EMBO Rep., 3 (7), p. 666–673, 2002, ISSN: 1469-221X. Résumé | Liens | BibTeX | Étiquettes: Animals, Anti-Bacterial Agents, Antimicrobial Cationic Peptides, Cell Adhesion Molecules, Fat Body, Gene Expression Regulation, Genes, Immunohistochemistry, Immunologic, Insect, Insect Proteins, Larva, M3i, Mass, Matrix-Assisted Laser Desorption-Ionization, Membrane Proteins, Receptors, reichhart, Reporter, Spectrometry, Transgenes @article{ligoxygakis_critical_2002, title = {Critical evaluation of the role of the Toll-like receptor 18-Wheeler in the host defense of Drosophila}, author = {Petros Ligoxygakis and Philippe Bulet and Jean-Marc Reichhart}, doi = {10.1093/embo-reports/kvf130}, issn = {1469-221X}, year = {2002}, date = {2002-01-01}, journal = {EMBO Rep.}, volume = {3}, number = {7}, pages = {666--673}, abstract = {Essential aspects of innate immune responses to microbial infections appear to be conserved between insects and mammals. In particular, in both groups, transmembrane receptors of the Toll superfamily play a crucial role in activating immune defenses. The Drosophila Toll family member 18-Wheeler had been proposed to sense Gram-negative infection and direct selective expression of peptides active against Gram-negative bacteria. Here we re-examine the role of 18-Wheeler and show that in adults it is dispensable for immune responses. In larvae, 18wheeler is required for normal fat body development, and in mutant larvae induction of all antimicrobial peptide genes, and not only of those directed against Gram-negative bacteria, is compromised. 18-Wheeler does not qualify as a pattern recognition receptor of Gram-negative bacteria.}, keywords = {Animals, Anti-Bacterial Agents, Antimicrobial Cationic Peptides, Cell Adhesion Molecules, Fat Body, Gene Expression Regulation, Genes, Immunohistochemistry, Immunologic, Insect, Insect Proteins, Larva, M3i, Mass, Matrix-Assisted Laser Desorption-Ionization, Membrane Proteins, Receptors, reichhart, Reporter, Spectrometry, Transgenes}, pubstate = {published}, tppubtype = {article} } Essential aspects of innate immune responses to microbial infections appear to be conserved between insects and mammals. In particular, in both groups, transmembrane receptors of the Toll superfamily play a crucial role in activating immune defenses. The Drosophila Toll family member 18-Wheeler had been proposed to sense Gram-negative infection and direct selective expression of peptides active against Gram-negative bacteria. Here we re-examine the role of 18-Wheeler and show that in adults it is dispensable for immune responses. In larvae, 18wheeler is required for normal fat body development, and in mutant larvae induction of all antimicrobial peptide genes, and not only of those directed against Gram-negative bacteria, is compromised. 18-Wheeler does not qualify as a pattern recognition receptor of Gram-negative bacteria. |
Tauszig-Delamasure, Servane; Bilak, Hana; Capovilla, Maria; Hoffmann, Jules A; Imler, Jean-Luc Drosophila MyD88 is required for the response to fungal and Gram-positive bacterial infections Article de journal Nature Immunology, 3 (1), p. 91–97, 2002, ISSN: 1529-2908. Résumé | Liens | BibTeX | Étiquettes: Adaptor Proteins, Amino Acid, Animals, Antigens, Antimicrobial Cationic Peptides, Cell Surface, Chromosome Mapping, Differentiation, Disease Susceptibility, Enterococcus faecalis, Epistasis, Escherichia coli, Female, Gene Expression Regulation, Genes, Genetic, Genetically Modified, Gram-Negative Bacteria, hoffmann, Hypocreales, imler, Immunologic, Insect, Insect Proteins, M3i, Membrane Glycoproteins, Micrococcus luteus, Myeloid Differentiation Factor 88, Protein Structure, Protein-Serine-Threonine Kinases, Receptors, Recombinant Fusion Proteins, Sequence Alignment, Sequence Homology, Signal Transducing, Tertiary, Toll-Like Receptors, Transfection @article{tauszig-delamasure_drosophila_2002, title = {Drosophila MyD88 is required for the response to fungal and Gram-positive bacterial infections}, author = {Servane Tauszig-Delamasure and Hana Bilak and Maria Capovilla and Jules A Hoffmann and Jean-Luc Imler}, doi = {10.1038/ni747}, issn = {1529-2908}, year = {2002}, date = {2002-01-01}, journal = {Nature Immunology}, volume = {3}, number = {1}, pages = {91--97}, abstract = {We report here the identification and functional characterization of DmMyD88, a gene encoding the Drosophila homolog of mammalian MyD88. DmMyD88 combines a Toll-IL-1R homology (TIR) domain and a death domain. Overexpression of DmMyD88 was sufficient to induce expression of the antifungal peptide Drosomycin, and induction of Drosomycin was markedly reduced in DmMyD88-mutant flies. DmMyD88 interacted with Toll through its TIR domain and required the death domain proteins Tube and Pelle to activate expression of Drs, which encodes Drosomycin. DmMyD88-mutant flies were highly susceptible to infection by fungi and Gram-positive bacteria, but resisted Gram-negative bacterial infection much as did wild-type flies. Phenotypic comparison of DmMyD88-mutant flies and MyD88-deficient mice showed essential differences in the control of Gram-negative infection in insects and mammals.}, keywords = {Adaptor Proteins, Amino Acid, Animals, Antigens, Antimicrobial Cationic Peptides, Cell Surface, Chromosome Mapping, Differentiation, Disease Susceptibility, Enterococcus faecalis, Epistasis, Escherichia coli, Female, Gene Expression Regulation, Genes, Genetic, Genetically Modified, Gram-Negative Bacteria, hoffmann, Hypocreales, imler, Immunologic, Insect, Insect Proteins, M3i, Membrane Glycoproteins, Micrococcus luteus, Myeloid Differentiation Factor 88, Protein Structure, Protein-Serine-Threonine Kinases, Receptors, Recombinant Fusion Proteins, Sequence Alignment, Sequence Homology, Signal Transducing, Tertiary, Toll-Like Receptors, Transfection}, pubstate = {published}, tppubtype = {article} } We report here the identification and functional characterization of DmMyD88, a gene encoding the Drosophila homolog of mammalian MyD88. DmMyD88 combines a Toll-IL-1R homology (TIR) domain and a death domain. Overexpression of DmMyD88 was sufficient to induce expression of the antifungal peptide Drosomycin, and induction of Drosomycin was markedly reduced in DmMyD88-mutant flies. DmMyD88 interacted with Toll through its TIR domain and required the death domain proteins Tube and Pelle to activate expression of Drs, which encodes Drosomycin. DmMyD88-mutant flies were highly susceptible to infection by fungi and Gram-positive bacteria, but resisted Gram-negative bacterial infection much as did wild-type flies. Phenotypic comparison of DmMyD88-mutant flies and MyD88-deficient mice showed essential differences in the control of Gram-negative infection in insects and mammals. |
Imler, Jean-Luc; Hoffmann, Jules A Toll receptors in Drosophila: a family of molecules regulating development and immunity Article de journal Current Topics in Microbiology and Immunology, 270 , p. 63–79, 2002, ISSN: 0070-217X. Résumé | BibTeX | Étiquettes: Animals, Cell Surface, Genetic, Gram-Negative Bacteria, hoffmann, imler, M3i, Receptors, Signal Transduction, Toll-Like Receptors, Transcription @article{imler_toll_2002, title = {Toll receptors in Drosophila: a family of molecules regulating development and immunity}, author = {Jean-Luc Imler and Jules A Hoffmann}, issn = {0070-217X}, year = {2002}, date = {2002-01-01}, journal = {Current Topics in Microbiology and Immunology}, volume = {270}, pages = {63--79}, abstract = {In recent years, Toll-like receptors (TLRs) have emerged as key receptors which detect microbes and initiate an inflammatory response. The Toll receptor was originally identified and characterized 14 years ago for its role in the embryonic development of the fruit-fly Drosophila melanogaster. Subsequently, it was also shown to be an essential component of the signaling pathway mediating the anti-fungal host defense in this model organism. New factors involved in the activation of the Toll receptor or in intracytoplasmic signaling during the immune response in Drosophila have recently been identified. The existence of significant functional differences between mammalian TLRs and Drosophila Toll receptors is also becoming apparent.}, keywords = {Animals, Cell Surface, Genetic, Gram-Negative Bacteria, hoffmann, imler, M3i, Receptors, Signal Transduction, Toll-Like Receptors, Transcription}, pubstate = {published}, tppubtype = {article} } In recent years, Toll-like receptors (TLRs) have emerged as key receptors which detect microbes and initiate an inflammatory response. The Toll receptor was originally identified and characterized 14 years ago for its role in the embryonic development of the fruit-fly Drosophila melanogaster. Subsequently, it was also shown to be an essential component of the signaling pathway mediating the anti-fungal host defense in this model organism. New factors involved in the activation of the Toll receptor or in intracytoplasmic signaling during the immune response in Drosophila have recently been identified. The existence of significant functional differences between mammalian TLRs and Drosophila Toll receptors is also becoming apparent. |
2001 |
Michel, T; Reichhart, Jean-Marc; Hoffmann, Jules A; Royet, Julien Drosophila Toll is activated by Gram-positive bacteria through a circulating peptidoglycan recognition protein Article de journal Nature, 414 (6865), p. 756–759, 2001, ISSN: 0028-0836. Résumé | Liens | BibTeX | Étiquettes: Amino Acid, Animals, Anti-Bacterial Agents, Anti-Infective Agents, Bacillus thuringiensis, Carrier Proteins, Cell Surface, Chromosome Mapping, Enterococcus faecalis, Fungi, Genes, Gram-Positive Bacteria, Hemolymph, hoffmann, Humans, Insect, Insect Proteins, M3i, Membrane Glycoproteins, Micrococcus luteus, Mutation, Receptors, reichhart, Sequence Homology, Toll-Like Receptors @article{michel_drosophila_2001, title = {Drosophila Toll is activated by Gram-positive bacteria through a circulating peptidoglycan recognition protein}, author = {T Michel and Jean-Marc Reichhart and Jules A Hoffmann and Julien Royet}, doi = {10.1038/414756a}, issn = {0028-0836}, year = {2001}, date = {2001-12-01}, journal = {Nature}, volume = {414}, number = {6865}, pages = {756--759}, abstract = {Microbial infection activates two distinct intracellular signalling cascades in the immune-responsive fat body of Drosophila. Gram-positive bacteria and fungi predominantly induce the Toll signalling pathway, whereas Gram-negative bacteria activate the Imd pathway. Loss-of-function mutants in either pathway reduce the resistance to corresponding infections. Genetic screens have identified a range of genes involved in these intracellular signalling cascades, but how they are activated by microbial infection is largely unknown. Activation of the transmembrane receptor Toll requires a proteolytically cleaved form of an extracellular cytokine-like polypeptide, Spätzle, suggesting that Toll does not itself function as a bona fide recognition receptor of microbial patterns. This is in apparent contrast with the mammalian Toll-like receptors and raises the question of which host molecules actually recognize microbial patterns to activate Toll through Spätzle. Here we present a mutation that blocks Toll activation by Gram-positive bacteria and significantly decreases resistance to this type of infection. The mutation semmelweis (seml) inactivates the gene encoding a peptidoglycan recognition protein (PGRP-SA). Interestingly, seml does not affect Toll activation by fungal infection, indicating the existence of a distinct recognition system for fungi to activate the Toll pathway.}, keywords = {Amino Acid, Animals, Anti-Bacterial Agents, Anti-Infective Agents, Bacillus thuringiensis, Carrier Proteins, Cell Surface, Chromosome Mapping, Enterococcus faecalis, Fungi, Genes, Gram-Positive Bacteria, Hemolymph, hoffmann, Humans, Insect, Insect Proteins, M3i, Membrane Glycoproteins, Micrococcus luteus, Mutation, Receptors, reichhart, Sequence Homology, Toll-Like Receptors}, pubstate = {published}, tppubtype = {article} } Microbial infection activates two distinct intracellular signalling cascades in the immune-responsive fat body of Drosophila. Gram-positive bacteria and fungi predominantly induce the Toll signalling pathway, whereas Gram-negative bacteria activate the Imd pathway. Loss-of-function mutants in either pathway reduce the resistance to corresponding infections. Genetic screens have identified a range of genes involved in these intracellular signalling cascades, but how they are activated by microbial infection is largely unknown. Activation of the transmembrane receptor Toll requires a proteolytically cleaved form of an extracellular cytokine-like polypeptide, Spätzle, suggesting that Toll does not itself function as a bona fide recognition receptor of microbial patterns. This is in apparent contrast with the mammalian Toll-like receptors and raises the question of which host molecules actually recognize microbial patterns to activate Toll through Spätzle. Here we present a mutation that blocks Toll activation by Gram-positive bacteria and significantly decreases resistance to this type of infection. The mutation semmelweis (seml) inactivates the gene encoding a peptidoglycan recognition protein (PGRP-SA). Interestingly, seml does not affect Toll activation by fungal infection, indicating the existence of a distinct recognition system for fungi to activate the Toll pathway. |
Postawski, K; Olech-Fudali, E; Korobowicz, E; Jakowicki, J A; Keith, G; Baranowski, W [Hydrophobic DNA adducts in relationship to estrogen and progesterone receptors content in human uterine cancer.] Article de journal Ginekol Pol, 72 (9), p. 709-16, 2001, (0017-0011 Journal Article). Résumé | BibTeX | Étiquettes: Abstract, Adducts/*analysis, Autoradiography, DNA, English, Estrogen/*analysis, Female, Human, Neoplasm/*analysis, Neoplasms/genetics/*pathology, Progesterone/*analysis, Receptors, Uterine @article{, title = {[Hydrophobic DNA adducts in relationship to estrogen and progesterone receptors content in human uterine cancer.]}, author = { K. Postawski and E. Olech-Fudali and E. Korobowicz and J. A. Jakowicki and G. Keith and W. Baranowski}, year = {2001}, date = {2001-01-01}, journal = {Ginekol Pol}, volume = {72}, number = {9}, pages = {709-16}, abstract = {OBJECTIVE: Determination of the relationship between hydrophobic DNA adducts (A) and estrogen receptors (ER) and progesterone (PR) receptor status in uterine cancers. METHODS: Using the P1 enriched version of 32P-postlabeling for hydrophobic DNA adducts detection on polyethyleneimine (PEI) cellulose thin layer chromatograms (TLC) we examined 11 uterine cancer DNAs. The quantification of the adducts was performed by Cerenkov counting of the spots. ER and PR status was recognized histochemically and H-score estimate was performed for each investigated cancer tissue. Patterns of uterine cancer DNA adducts were compared to the maps of adducts recognized in normal human endometrium. RESULTS: In three of the studied uterine cancers there was no positive staining of ER and PR; in one case there was a weak ER staining but PR staining was negative. In ER negative tumors the A level was significantly higher than in ER positive cancers (138.1 +/- 64.1 vs. 49.7 +/- 26.8 adducts per 10(9) nucleotides, respectively, p < 0.05). Highest A levels were found in two ER and PR negative G3 metastatic tumors. Finally, in all investigated cancers there was a strong, inverse correlation between ER content and A level (r = -0.67, p < 0.03). In addition, the correlation between PR level and A was of borderline significance (r = -0.6}, note = {0017-0011 Journal Article}, keywords = {Abstract, Adducts/*analysis, Autoradiography, DNA, English, Estrogen/*analysis, Female, Human, Neoplasm/*analysis, Neoplasms/genetics/*pathology, Progesterone/*analysis, Receptors, Uterine}, pubstate = {published}, tppubtype = {article} } OBJECTIVE: Determination of the relationship between hydrophobic DNA adducts (A) and estrogen receptors (ER) and progesterone (PR) receptor status in uterine cancers. METHODS: Using the P1 enriched version of 32P-postlabeling for hydrophobic DNA adducts detection on polyethyleneimine (PEI) cellulose thin layer chromatograms (TLC) we examined 11 uterine cancer DNAs. The quantification of the adducts was performed by Cerenkov counting of the spots. ER and PR status was recognized histochemically and H-score estimate was performed for each investigated cancer tissue. Patterns of uterine cancer DNA adducts were compared to the maps of adducts recognized in normal human endometrium. RESULTS: In three of the studied uterine cancers there was no positive staining of ER and PR; in one case there was a weak ER staining but PR staining was negative. In ER negative tumors the A level was significantly higher than in ER positive cancers (138.1 +/- 64.1 vs. 49.7 +/- 26.8 adducts per 10(9) nucleotides, respectively, p < 0.05). Highest A levels were found in two ER and PR negative G3 metastatic tumors. Finally, in all investigated cancers there was a strong, inverse correlation between ER content and A level (r = -0.67, p < 0.03). In addition, the correlation between PR level and A was of borderline significance (r = -0.6 |
Imler, Jean-Luc; Hoffmann, Jules A Toll receptors in innate immunity Article de journal Trends in Cell Biology, 11 (7), p. 304–311, 2001, ISSN: 0962-8924. Résumé | BibTeX | Étiquettes: Animals, Cell Surface, hoffmann, Humans, imler, Immunity, Immunologic, Innate, M3i, Membrane Glycoproteins, Membrane Proteins, Receptors, Toll-Like Receptors @article{imler_toll_2001, title = {Toll receptors in innate immunity}, author = {Jean-Luc Imler and Jules A Hoffmann}, issn = {0962-8924}, year = {2001}, date = {2001-01-01}, journal = {Trends in Cell Biology}, volume = {11}, number = {7}, pages = {304--311}, abstract = {Innate immunity is the first-line host defense of multicellular organisms that rapidly operates to limit infection upon exposure to infectious agents. In addition, the cells and molecules operating during this early stage of the immune response in vertebrates have a decisive impact on the shaping of the subsequent adaptive response. Genetic studies initially performed in the fruitfly Drosophila and later in mice have revealed the importance of proteins of the Toll family in the innate immune response. We present here our current understanding of the role of this evolutionary ancient family of proteins that are thought to function as cytokine receptors (Toll in Drosophila) or pattern-recognition receptors (TLRs in mammals) and activate similar, albeit non-identical, signal-transduction pathways in flies and mammals.}, keywords = {Animals, Cell Surface, hoffmann, Humans, imler, Immunity, Immunologic, Innate, M3i, Membrane Glycoproteins, Membrane Proteins, Receptors, Toll-Like Receptors}, pubstate = {published}, tppubtype = {article} } Innate immunity is the first-line host defense of multicellular organisms that rapidly operates to limit infection upon exposure to infectious agents. In addition, the cells and molecules operating during this early stage of the immune response in vertebrates have a decisive impact on the shaping of the subsequent adaptive response. Genetic studies initially performed in the fruitfly Drosophila and later in mice have revealed the importance of proteins of the Toll family in the innate immune response. We present here our current understanding of the role of this evolutionary ancient family of proteins that are thought to function as cytokine receptors (Toll in Drosophila) or pattern-recognition receptors (TLRs in mammals) and activate similar, albeit non-identical, signal-transduction pathways in flies and mammals. |
2000 |
Lagueux, Marie; Perrodou, E; Levashina, Elena A; Capovilla, Maria; Hoffmann, Jules A Constitutive expression of a complement-like protein in toll and JAK gain-of-function mutants of Drosophila Article de journal Proc. Natl. Acad. Sci. U.S.A., 97 (21), p. 11427–11432, 2000, ISSN: 0027-8424. Résumé | Liens | BibTeX | Étiquettes: alpha-Macroglobulins, Amino Acid, Animals, Cell Surface, Complement C3, Esters, Genetic, hoffmann, Insect Proteins, Janus Kinases, M3i, Membrane Glycoproteins, Mutation, Protein-Tyrosine Kinases, Proteins, Receptors, Sequence Homology, Sulfhydryl Compounds, Toll-Like Receptors, Transcription, Transcription Factors @article{lagueux_constitutive_2000, title = {Constitutive expression of a complement-like protein in toll and JAK gain-of-function mutants of Drosophila}, author = {Marie Lagueux and E Perrodou and Elena A Levashina and Maria Capovilla and Jules A Hoffmann}, doi = {10.1073/pnas.97.21.11427}, issn = {0027-8424}, year = {2000}, date = {2000-10-01}, journal = {Proc. Natl. Acad. Sci. U.S.A.}, volume = {97}, number = {21}, pages = {11427--11432}, abstract = {We show that Drosophila expresses four genes encoding proteins with significant similarities with the thiolester-containing proteins of the complement C3/alpha(2)-macroglobulin superfamily. The genes are transcribed at a low level during all stages of development, and their expression is markedly up-regulated after an immune challenge. For one of these genes, which is predominantly expressed in the larval fat body, we observe a constitutive expression in gain-of-function mutants of the Janus kinase (JAK) hop and a reduced inducibility in loss-of-function hop mutants. We also observe a constitutive expression in gain-of-function Toll mutants. We discuss the possible roles of these novel complement-like proteins in the Drosophila host defense.}, keywords = {alpha-Macroglobulins, Amino Acid, Animals, Cell Surface, Complement C3, Esters, Genetic, hoffmann, Insect Proteins, Janus Kinases, M3i, Membrane Glycoproteins, Mutation, Protein-Tyrosine Kinases, Proteins, Receptors, Sequence Homology, Sulfhydryl Compounds, Toll-Like Receptors, Transcription, Transcription Factors}, pubstate = {published}, tppubtype = {article} } We show that Drosophila expresses four genes encoding proteins with significant similarities with the thiolester-containing proteins of the complement C3/alpha(2)-macroglobulin superfamily. The genes are transcribed at a low level during all stages of development, and their expression is markedly up-regulated after an immune challenge. For one of these genes, which is predominantly expressed in the larval fat body, we observe a constitutive expression in gain-of-function mutants of the Janus kinase (JAK) hop and a reduced inducibility in loss-of-function hop mutants. We also observe a constitutive expression in gain-of-function Toll mutants. We discuss the possible roles of these novel complement-like proteins in the Drosophila host defense. |
Rutschmann, Sophie; Jung, Alain C; Zhou, R; Silverman, N; Hoffmann, Jules A; Ferrandon, Dominique Role of Drosophila IKK gamma in a toll-independent antibacterial immune response Article de journal Nat. Immunol., 1 (4), p. 342–347, 2000, ISSN: 1529-2908. Résumé | Liens | BibTeX | Étiquettes: Animals, Antigens, Bacterial, Cell Surface, ferrandon, Gene Expression Regulation, hoffmann, I-kappa B Kinase, Immunity, Innate, Insect Proteins, M3i, Membrane Glycoproteins, Protein-Serine-Threonine Kinases, Receptors, Signal Transduction, Toll-Like Receptors, Transcription Factors @article{rutschmann_role_2000, title = {Role of Drosophila IKK gamma in a toll-independent antibacterial immune response}, author = {Sophie Rutschmann and Alain C Jung and R Zhou and N Silverman and Jules A Hoffmann and Dominique Ferrandon}, doi = {10.1038/79801}, issn = {1529-2908}, year = {2000}, date = {2000-10-01}, journal = {Nat. Immunol.}, volume = {1}, number = {4}, pages = {342--347}, abstract = {We have generated, by ethylmethane sulfonate mutagenesis, loss-of-function mutants in the Drosophila homolog of the mammalian I-kappa B kinase (IKK) complex component IKK gamma (also called NEMO). Our data show that Drosophila IKK gamma is required for the Relish-dependent immune induction of the genes encoding antibacterial peptides and for resistance to infections by Escherichia coli. However, it is not required for the Toll-DIF-dependent antifungal host defense. The results indicate distinct control mechanisms of the Rel-like transactivators DIF and Relish in the Drosophila innate immune response and show that Drosophila Toll does not signal through a IKK gamma-dependent signaling complex. Thus, in contrast to the vertebrate inflammatory response, IKK gamma is required for the activation of only one immune signaling pathway in Drosophila.}, keywords = {Animals, Antigens, Bacterial, Cell Surface, ferrandon, Gene Expression Regulation, hoffmann, I-kappa B Kinase, Immunity, Innate, Insect Proteins, M3i, Membrane Glycoproteins, Protein-Serine-Threonine Kinases, Receptors, Signal Transduction, Toll-Like Receptors, Transcription Factors}, pubstate = {published}, tppubtype = {article} } We have generated, by ethylmethane sulfonate mutagenesis, loss-of-function mutants in the Drosophila homolog of the mammalian I-kappa B kinase (IKK) complex component IKK gamma (also called NEMO). Our data show that Drosophila IKK gamma is required for the Relish-dependent immune induction of the genes encoding antibacterial peptides and for resistance to infections by Escherichia coli. However, it is not required for the Toll-DIF-dependent antifungal host defense. The results indicate distinct control mechanisms of the Rel-like transactivators DIF and Relish in the Drosophila innate immune response and show that Drosophila Toll does not signal through a IKK gamma-dependent signaling complex. Thus, in contrast to the vertebrate inflammatory response, IKK gamma is required for the activation of only one immune signaling pathway in Drosophila. |
Tauszig, Servane; Jouanguy, Emmanuelle; Hoffmann, Jules A; Imler, Jean-Luc Toll-related receptors and the control of antimicrobial peptide expression in Drosophila Article de journal Proceedings of the National Academy of Sciences of the United States of America, 97 (19), p. 10520–10525, 2000, ISSN: 0027-8424. Résumé | Liens | BibTeX | Étiquettes: Amino Acid, Animals, Anti-Bacterial Agents, Blotting, Cell Line, Cell Surface, hoffmann, imler, M3i, Membrane Glycoproteins, Multigene Family, Northern, Peptides, Receptors, Reverse Transcriptase Polymerase Chain Reaction, Sequence Homology, Toll-Like Receptor 2, Toll-Like Receptor 4, Toll-Like Receptor 5, Toll-Like Receptors @article{tauszig_toll-related_2000, title = {Toll-related receptors and the control of antimicrobial peptide expression in Drosophila}, author = {Servane Tauszig and Emmanuelle Jouanguy and Jules A Hoffmann and Jean-Luc Imler}, doi = {10.1073/pnas.180130797}, issn = {0027-8424}, year = {2000}, date = {2000-09-01}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {97}, number = {19}, pages = {10520--10525}, abstract = {Insects defend themselves against infectious microorganisms by synthesizing potent antimicrobial peptides. Drosophila has appeared in recent years as a favorable model to study this innate host defense. A genetic analysis of the regulation of the antifungal peptide drosomycin has demonstrated a key role for the transmembrane receptor Toll, which prompted the search for mammalian homologs. Two of these, Toll-like receptor (TLR)2 and TLR4, recently were shown to play a critical role in innate immunity against bacteria. Here we describe six additional Toll-related genes (Toll-3 to Toll-8) in Drosophila in addition to 18-wheeler. Two of these genes, Toll-3 and Toll-4, are expressed at a low level. Toll-6, -7, and -8, on the other hand, are expressed at high levels during embryogenesis and molting, suggesting that, like Toll and 18w, they perform developmental functions. Finally, Toll-5 is expressed only in larvae and adults. By using chimeric constructs, we have tested the capacity of the signaling Toll/IL-1R homology domains of these receptors to activate antimicrobial peptide promoters and found that only Toll and Toll-5 can activate the drosomycin promoter in transfected cells, thus demonstrating specificity at the level of the Toll/IL-1R homology domain. In contrast, none of these constructs activated antibacterial peptide promoters, suggesting that Toll-related receptors are not involved in the regulation of antibacterial peptide expression. This result was independently confirmed by the demonstration that a dominant-negative version of the kinase Pelle can block induction of drosomycin by the cytokine Spaetzle, but does not affect induction of the antibacterial peptide attacin by lipopolysaccharide.}, keywords = {Amino Acid, Animals, Anti-Bacterial Agents, Blotting, Cell Line, Cell Surface, hoffmann, imler, M3i, Membrane Glycoproteins, Multigene Family, Northern, Peptides, Receptors, Reverse Transcriptase Polymerase Chain Reaction, Sequence Homology, Toll-Like Receptor 2, Toll-Like Receptor 4, Toll-Like Receptor 5, Toll-Like Receptors}, pubstate = {published}, tppubtype = {article} } Insects defend themselves against infectious microorganisms by synthesizing potent antimicrobial peptides. Drosophila has appeared in recent years as a favorable model to study this innate host defense. A genetic analysis of the regulation of the antifungal peptide drosomycin has demonstrated a key role for the transmembrane receptor Toll, which prompted the search for mammalian homologs. Two of these, Toll-like receptor (TLR)2 and TLR4, recently were shown to play a critical role in innate immunity against bacteria. Here we describe six additional Toll-related genes (Toll-3 to Toll-8) in Drosophila in addition to 18-wheeler. Two of these genes, Toll-3 and Toll-4, are expressed at a low level. Toll-6, -7, and -8, on the other hand, are expressed at high levels during embryogenesis and molting, suggesting that, like Toll and 18w, they perform developmental functions. Finally, Toll-5 is expressed only in larvae and adults. By using chimeric constructs, we have tested the capacity of the signaling Toll/IL-1R homology domains of these receptors to activate antimicrobial peptide promoters and found that only Toll and Toll-5 can activate the drosomycin promoter in transfected cells, thus demonstrating specificity at the level of the Toll/IL-1R homology domain. In contrast, none of these constructs activated antibacterial peptide promoters, suggesting that Toll-related receptors are not involved in the regulation of antibacterial peptide expression. This result was independently confirmed by the demonstration that a dominant-negative version of the kinase Pelle can block induction of drosomycin by the cytokine Spaetzle, but does not affect induction of the antibacterial peptide attacin by lipopolysaccharide. |
Imler, Jean-Luc; Hoffmann, Jules A Signaling mechanisms in the antimicrobial host defense of Drosophila Article de journal Current Opinion in Microbiology, 3 (1), p. 16–22, 2000, ISSN: 1369-5274. Résumé | BibTeX | Étiquettes: Animals, Anti-Infective Agents, Cell Surface, Gene Expression Regulation, Genes, hoffmann, imler, Insect, Insect Proteins, M3i, Membrane Glycoproteins, Receptors, Signal Transduction, Toll-Like Receptors @article{imler_signaling_2000, title = {Signaling mechanisms in the antimicrobial host defense of Drosophila}, author = {Jean-Luc Imler and Jules A Hoffmann}, issn = {1369-5274}, year = {2000}, date = {2000-02-01}, journal = {Current Opinion in Microbiology}, volume = {3}, number = {1}, pages = {16--22}, abstract = {Drosophila has appeared in recent years as a powerful model to study innate immunity. Several papers published in the past year shed light on the role of the three Rel proteins Dorsal, Dif and Relish in the regulation of antimicrobial peptide expression. In addition, the discovery that a blood serine protease inhibitor is involved in the control of the antifungal response indicates that Toll is activated upon triggering of a proteolytic cascade and does not function as a Drosophila pattern recognition receptor.}, keywords = {Animals, Anti-Infective Agents, Cell Surface, Gene Expression Regulation, Genes, hoffmann, imler, Insect, Insect Proteins, M3i, Membrane Glycoproteins, Receptors, Signal Transduction, Toll-Like Receptors}, pubstate = {published}, tppubtype = {article} } Drosophila has appeared in recent years as a powerful model to study innate immunity. Several papers published in the past year shed light on the role of the three Rel proteins Dorsal, Dif and Relish in the regulation of antimicrobial peptide expression. In addition, the discovery that a blood serine protease inhibitor is involved in the control of the antifungal response indicates that Toll is activated upon triggering of a proteolytic cascade and does not function as a Drosophila pattern recognition receptor. |
Postawski, K; Olech-Fudali, E; Jakowicki, J A; Korobowicz, E; Keith, G; Baranowski, W [Overall genomic DNA methylation in relation to estrogen] Article de journal Ginekol Pol, 71 (9), p. 1206-11, 2000, (0017-0011 Journal Article). Résumé | BibTeX | Étiquettes: 80, Abstract, Aged, and, Biopsy, DNA, English, Estrogen/*metabolism, Female, Gov't, Human, Methylases/metabolism, Methylation, Middle, modification, Neoplasms/*metabolism/*pathology, Non-U.S., over, Progesterone/*metabolism, Receptors, Support, Uterine, Uterus/*metabolism/pathology @article{, title = {[Overall genomic DNA methylation in relation to estrogen]}, author = { K. Postawski and E. Olech-Fudali and J. A. Jakowicki and E. Korobowicz and G. Keith and W. Baranowski}, year = {2000}, date = {2000-01-01}, journal = {Ginekol Pol}, volume = {71}, number = {9}, pages = {1206-11}, abstract = {Overall genomic DNA methylation was analyzed using enzymatic digestion into nucleotides, 32P postlabeling, two-dimensional thin-layer chromatography on cellulose plates and phosphobioimaging quantitation, in relation to immunohistochemically measured estrogen (ER) and progesterone receptor (PR) status of 15 uterine cancers. Mean 5-methyldeoxycytosine (m5dC) content did not differ between ER-positive and ER-negative neoplasms. Highest values of m5dC were noted both in ER-negative and ER-positive tumors. Additionally, there was no low DNA methylation in ER negative uterine cancer tissues. Decrease of the overall genomic DNA methylation could be related to the increase of ER/PR ratio, however it was not significant in our investigation. The potential role of steroid receptors status in uterine cancer tissue is discussed.}, note = {0017-0011 Journal Article}, keywords = {80, Abstract, Aged, and, Biopsy, DNA, English, Estrogen/*metabolism, Female, Gov't, Human, Methylases/metabolism, Methylation, Middle, modification, Neoplasms/*metabolism/*pathology, Non-U.S., over, Progesterone/*metabolism, Receptors, Support, Uterine, Uterus/*metabolism/pathology}, pubstate = {published}, tppubtype = {article} } Overall genomic DNA methylation was analyzed using enzymatic digestion into nucleotides, 32P postlabeling, two-dimensional thin-layer chromatography on cellulose plates and phosphobioimaging quantitation, in relation to immunohistochemically measured estrogen (ER) and progesterone receptor (PR) status of 15 uterine cancers. Mean 5-methyldeoxycytosine (m5dC) content did not differ between ER-positive and ER-negative neoplasms. Highest values of m5dC were noted both in ER-negative and ER-positive tumors. Additionally, there was no low DNA methylation in ER negative uterine cancer tissues. Decrease of the overall genomic DNA methylation could be related to the increase of ER/PR ratio, however it was not significant in our investigation. The potential role of steroid receptors status in uterine cancer tissue is discussed. |
Imler, Jean-Luc; Tauszig, Servane; Jouanguy, Emmanuelle; Forestier, C; Hoffmann, Jules A LPS-induced immune response in Drosophila Article de journal Journal of Endotoxin Research, 6 (6), p. 459–462, 2000, ISSN: 0968-0519. Résumé | BibTeX | Étiquettes: Animals, Biological, Cell Line, Cell Surface, Defensins, Genes, Genetic, hoffmann, imler, Insect, Insect Proteins, Lipopolysaccharides, M3i, Membrane Glycoproteins, Models, Mutation, Promoter Regions, Receptors, Signal Transduction, Toll-Like Receptors @article{imler_lps-induced_2000, title = {LPS-induced immune response in Drosophila}, author = {Jean-Luc Imler and Servane Tauszig and Emmanuelle Jouanguy and C Forestier and Jules A Hoffmann}, issn = {0968-0519}, year = {2000}, date = {2000-01-01}, journal = {Journal of Endotoxin Research}, volume = {6}, number = {6}, pages = {459--462}, abstract = {The study of the regulation of the inducible synthesis of antimicrobial peptides in Drosophila melanogaster has established this insect as a powerful model in which to study innate immunity. In particular, the molecular characterization of the regulatory pathway controlling the antifungal peptide drosomycin has revealed the importance of Toll receptors in innate immunity. We report here that injection of LPS into flies induces an immune response, suggesting that LPS receptors are used in Drosophila to detect Gram-negative bacteria infection. We have identified in the recently sequenced genome of Drosophila eight genes coding for Toll-like receptors in addition to Toll, which may function as LPS receptors. However, overexpression of a selection of these genes in tissue-culture cells does not result in up-regulation of the antibacterial peptide genes. These results are discussed in light of the recent data from genetic screens aimed at identifying the genes controlling the antibacterial response in Drosophila.}, keywords = {Animals, Biological, Cell Line, Cell Surface, Defensins, Genes, Genetic, hoffmann, imler, Insect, Insect Proteins, Lipopolysaccharides, M3i, Membrane Glycoproteins, Models, Mutation, Promoter Regions, Receptors, Signal Transduction, Toll-Like Receptors}, pubstate = {published}, tppubtype = {article} } The study of the regulation of the inducible synthesis of antimicrobial peptides in Drosophila melanogaster has established this insect as a powerful model in which to study innate immunity. In particular, the molecular characterization of the regulatory pathway controlling the antifungal peptide drosomycin has revealed the importance of Toll receptors in innate immunity. We report here that injection of LPS into flies induces an immune response, suggesting that LPS receptors are used in Drosophila to detect Gram-negative bacteria infection. We have identified in the recently sequenced genome of Drosophila eight genes coding for Toll-like receptors in addition to Toll, which may function as LPS receptors. However, overexpression of a selection of these genes in tissue-culture cells does not result in up-regulation of the antibacterial peptide genes. These results are discussed in light of the recent data from genetic screens aimed at identifying the genes controlling the antibacterial response in Drosophila. |
Imler, Jean-Luc; Hoffmann, Jules A Toll and Toll-like proteins: an ancient family of receptors signaling infection Article de journal Reviews in Immunogenetics, 2 (3), p. 294–304, 2000, ISSN: 1398-1714. Résumé | BibTeX | Étiquettes: Adaptor Proteins, Animals, Antigens, Autoantigens, CD14, Cell Adhesion Molecules, Cell Surface, Differentiation, DNA-Binding Proteins, Gene Expression Regulation, hoffmann, I-kappa B Proteins, imler, Immunity, Immunologic, infection, Innate, Insect Proteins, Interleukin-1 Receptor-Associated Kinases, Knockout, Larva, Lipopolysaccharides, M3i, Mammals, MAP Kinase Signaling System, Membrane Glycoproteins, Membrane Proteins, Mice, Multigene Family, Myeloid Differentiation Factor 88, NF-kappa B, peptidoglycan, Phosphorylation, Post-Translational, Protein Kinases, Protein Processing, Protein Structure, Receptors, Recombinant Fusion Proteins, Signal Transducing, Signal Transduction, Teichoic Acids, Tertiary, Toll-Like Receptor 4, Toll-Like Receptor 5, Toll-Like Receptor 6, Toll-Like Receptor 9, Toll-Like Receptors, Ubiquitins @article{imler_toll_2000, title = {Toll and Toll-like proteins: an ancient family of receptors signaling infection}, author = {Jean-Luc Imler and Jules A Hoffmann}, issn = {1398-1714}, year = {2000}, date = {2000-01-01}, journal = {Reviews in Immunogenetics}, volume = {2}, number = {3}, pages = {294--304}, abstract = {Innate immunity is the first-line host defense of multicellular organisms that rapidly operates to limit infection upon exposure to microbes. It involves intracellular signaling pathways in the fruit-fly Drosophila and in mammals that show striking similarities. Recent genetic and biochemical data have revealed, in particular, that proteins of the Toll family play a critical role in the immediate response to infection. We review here the recent developments on the structural and functional characterization of this evolutionary ancient and important family of proteins, which can function as cytokine receptors (Toll in Drosophila) or pattern recognition receptors (TLR4 in mammals) and activate similar, albeit non identical signal transduction pathways, in flies and mammals.}, keywords = {Adaptor Proteins, Animals, Antigens, Autoantigens, CD14, Cell Adhesion Molecules, Cell Surface, Differentiation, DNA-Binding Proteins, Gene Expression Regulation, hoffmann, I-kappa B Proteins, imler, Immunity, Immunologic, infection, Innate, Insect Proteins, Interleukin-1 Receptor-Associated Kinases, Knockout, Larva, Lipopolysaccharides, M3i, Mammals, MAP Kinase Signaling System, Membrane Glycoproteins, Membrane Proteins, Mice, Multigene Family, Myeloid Differentiation Factor 88, NF-kappa B, peptidoglycan, Phosphorylation, Post-Translational, Protein Kinases, Protein Processing, Protein Structure, Receptors, Recombinant Fusion Proteins, Signal Transducing, Signal Transduction, Teichoic Acids, Tertiary, Toll-Like Receptor 4, Toll-Like Receptor 5, Toll-Like Receptor 6, Toll-Like Receptor 9, Toll-Like Receptors, Ubiquitins}, pubstate = {published}, tppubtype = {article} } Innate immunity is the first-line host defense of multicellular organisms that rapidly operates to limit infection upon exposure to microbes. It involves intracellular signaling pathways in the fruit-fly Drosophila and in mammals that show striking similarities. Recent genetic and biochemical data have revealed, in particular, that proteins of the Toll family play a critical role in the immediate response to infection. We review here the recent developments on the structural and functional characterization of this evolutionary ancient and important family of proteins, which can function as cytokine receptors (Toll in Drosophila) or pattern recognition receptors (TLR4 in mammals) and activate similar, albeit non identical signal transduction pathways, in flies and mammals. |
1999 |
Levashina, Elena A; Langley, E; Green, C; Gubb, David; Ashburner, M; Hoffmann, Jules A; Reichhart, Jean-Marc Constitutive activation of toll-mediated antifungal defense in serpin-deficient Drosophila Article de journal Science, 285 (5435), p. 1917–1919, 1999, ISSN: 0036-8075. Résumé | BibTeX | Étiquettes: Animals, Antifungal Agents, Antimicrobial Cationic Peptides, Body Patterning, Cell Surface, Escherichia coli, Genes, Hemolymph, hoffmann, Insect, Insect Proteins, M3i, Membrane Glycoproteins, Micrococcus luteus, Mutagenesis, Peptides, Receptors, Recombinant Fusion Proteins, reichhart, Serine Proteinase Inhibitors, Serpins, Signal Transduction, Toll-Like Receptors, Up-Regulation @article{levashina_constitutive_1999, title = {Constitutive activation of toll-mediated antifungal defense in serpin-deficient Drosophila}, author = {Elena A Levashina and E Langley and C Green and David Gubb and M Ashburner and Jules A Hoffmann and Jean-Marc Reichhart}, issn = {0036-8075}, year = {1999}, date = {1999-09-01}, journal = {Science}, volume = {285}, number = {5435}, pages = {1917--1919}, abstract = {The antifungal defense of Drosophila is controlled by the spaetzle/Toll/cactus gene cassette. Here, a loss-of-function mutation in the gene encoding a blood serine protease inhibitor, Spn43Ac, was shown to lead to constitutive expression of the antifungal peptide drosomycin, and this effect was mediated by the spaetzle and Toll gene products. Spaetzle was cleaved by proteolytic enzymes to its active ligand form shortly after immune challenge, and cleaved Spaetzle was constitutively present in Spn43Ac-deficient flies. Hence, Spn43Ac negatively regulates the Toll signaling pathway, and Toll does not function as a pattern recognition receptor in the Drosophila host defense.}, keywords = {Animals, Antifungal Agents, Antimicrobial Cationic Peptides, Body Patterning, Cell Surface, Escherichia coli, Genes, Hemolymph, hoffmann, Insect, Insect Proteins, M3i, Membrane Glycoproteins, Micrococcus luteus, Mutagenesis, Peptides, Receptors, Recombinant Fusion Proteins, reichhart, Serine Proteinase Inhibitors, Serpins, Signal Transduction, Toll-Like Receptors, Up-Regulation}, pubstate = {published}, tppubtype = {article} } The antifungal defense of Drosophila is controlled by the spaetzle/Toll/cactus gene cassette. Here, a loss-of-function mutation in the gene encoding a blood serine protease inhibitor, Spn43Ac, was shown to lead to constitutive expression of the antifungal peptide drosomycin, and this effect was mediated by the spaetzle and Toll gene products. Spaetzle was cleaved by proteolytic enzymes to its active ligand form shortly after immune challenge, and cleaved Spaetzle was constitutively present in Spn43Ac-deficient flies. Hence, Spn43Ac negatively regulates the Toll signaling pathway, and Toll does not function as a pattern recognition receptor in the Drosophila host defense. |
Manfruelli, P; Reichhart, Jean-Marc; Steward, R; Hoffmann, Jules A; Lemaitre, Bruno A mosaic analysis in Drosophila fat body cells of the control of antimicrobial peptide genes by the Rel proteins Dorsal and DIF Article de journal EMBO J., 18 (12), p. 3380–3391, 1999, ISSN: 0261-4189. Résumé | Liens | BibTeX | Étiquettes: Animals, Anti-Infective Agents, Cell Surface, Clone Cells, DNA-Binding Proteins, Fat Body, Female, Gene Expression Regulation, Genes, hoffmann, Insect, Insect Proteins, Larva, M3i, Male, Membrane Glycoproteins, Mosaicism, Mutation, Nuclear Proteins, Phosphoproteins, Receptors, reichhart, Reporter, Signal Transduction, Toll-Like Receptors, Transcription Factors @article{manfruelli_mosaic_1999, title = {A mosaic analysis in Drosophila fat body cells of the control of antimicrobial peptide genes by the Rel proteins Dorsal and DIF}, author = {P Manfruelli and Jean-Marc Reichhart and R Steward and Jules A Hoffmann and Bruno Lemaitre}, doi = {10.1093/emboj/18.12.3380}, issn = {0261-4189}, year = {1999}, date = {1999-06-01}, journal = {EMBO J.}, volume = {18}, number = {12}, pages = {3380--3391}, abstract = {Expression of the gene encoding the antifungal peptide Drosomycin in Drosophila adults is controlled by the Toll signaling pathway. The Rel proteins Dorsal and DIF (Dorsal-related immunity factor) are possible candidates for the transactivating protein in the Toll pathway that directly regulates the drosomycin gene. We have examined the requirement of Dorsal and DIF for drosomycin expression in larval fat body cells, the predominant immune-responsive tissue, using the yeast site-specific flp/FRT recombination system to generate cell clones homozygous for a deficiency uncovering both the dorsal and the dif genes. Here we show that in the absence of both genes, the immune-inducibility of drosomycin is lost but can be rescued by overexpression of either dorsal or dif under the control of a heat-shock promoter. This result suggests a functional redundancy between both Rel proteins in the control of drosomycin gene expression in the larvae of Drosophila. Interestingly, the gene encoding the antibacterial peptide Diptericin remains fully inducible in the absence of the dorsal and dif genes. Finally, we have used fat body cell clones homozygous for various mutations to show that a linear activation cascade Spaetzle--textgreater Toll--textgreaterCactus--textgreaterDorsal/DIF leads to the induction of the drosomycin gene in larval fat body cells.}, keywords = {Animals, Anti-Infective Agents, Cell Surface, Clone Cells, DNA-Binding Proteins, Fat Body, Female, Gene Expression Regulation, Genes, hoffmann, Insect, Insect Proteins, Larva, M3i, Male, Membrane Glycoproteins, Mosaicism, Mutation, Nuclear Proteins, Phosphoproteins, Receptors, reichhart, Reporter, Signal Transduction, Toll-Like Receptors, Transcription Factors}, pubstate = {published}, tppubtype = {article} } Expression of the gene encoding the antifungal peptide Drosomycin in Drosophila adults is controlled by the Toll signaling pathway. The Rel proteins Dorsal and DIF (Dorsal-related immunity factor) are possible candidates for the transactivating protein in the Toll pathway that directly regulates the drosomycin gene. We have examined the requirement of Dorsal and DIF for drosomycin expression in larval fat body cells, the predominant immune-responsive tissue, using the yeast site-specific flp/FRT recombination system to generate cell clones homozygous for a deficiency uncovering both the dorsal and the dif genes. Here we show that in the absence of both genes, the immune-inducibility of drosomycin is lost but can be rescued by overexpression of either dorsal or dif under the control of a heat-shock promoter. This result suggests a functional redundancy between both Rel proteins in the control of drosomycin gene expression in the larvae of Drosophila. Interestingly, the gene encoding the antibacterial peptide Diptericin remains fully inducible in the absence of the dorsal and dif genes. Finally, we have used fat body cell clones homozygous for various mutations to show that a linear activation cascade Spaetzle--textgreater Toll--textgreaterCactus--textgreaterDorsal/DIF leads to the induction of the drosomycin gene in larval fat body cells. |
1998 |
Ferrandon, Dominique; Jung, Alain C; Criqui, M; Lemaitre, Bruno; Uttenweiler-Joseph, S; Michaut, Lydia; Reichhart, Jean-Marc; Hoffmann, Jules A A drosomycin-GFP reporter transgene reveals a local immune response in Drosophila that is not dependent on the Toll pathway Article de journal EMBO J., 17 (5), p. 1217–1227, 1998, ISSN: 0261-4189. Résumé | Liens | BibTeX | Étiquettes: Animals, bacteria, Cell Surface, Developmental, Digestive System, Epithelium, Fat Body, Female, ferrandon, Fungal, Gene Expression Regulation, Genes, Green Fluorescent Proteins, hoffmann, Insect Proteins, Larva, Luminescent Proteins, M3i, Male, Membrane Glycoproteins, Organ Specificity, Receptors, reichhart, Reporter, Respiratory System, Spores, Toll-Like Receptors, Trachea, Transgenes @article{ferrandon_drosomycin-gfp_1998, title = {A drosomycin-GFP reporter transgene reveals a local immune response in Drosophila that is not dependent on the Toll pathway}, author = {Dominique Ferrandon and Alain C Jung and M Criqui and Bruno Lemaitre and S Uttenweiler-Joseph and Lydia Michaut and Jean-Marc Reichhart and Jules A Hoffmann}, doi = {10.1093/emboj/17.5.1217}, issn = {0261-4189}, year = {1998}, date = {1998-08-01}, journal = {EMBO J.}, volume = {17}, number = {5}, pages = {1217--1227}, abstract = {A hallmark of the systemic antimicrobial response of Drosophila is the synthesis by the fat body of several antimicrobial peptides which are released into the hemolymph in response to a septic injury. One of these peptides, drosomycin, is active primarily against fungi. Using a drosomycin-green fluorescent protein (GFP) reporter gene, we now show that in addition to the fat body, a variety of epithelial tissues that are in direct contact with the external environment, including those of the respiratory, digestive and reproductive tracts, can express the antifungal peptide, suggesting a local response to infections affecting these barrier tissues. As is the case for vertebrate epithelia, insect epithelia appear to be more than passive physical barriers and are likely to constitute an active component of innate immunity. We also show that, in contrast to the systemic antifungal response, this local immune response is independent of the Toll pathway.}, keywords = {Animals, bacteria, Cell Surface, Developmental, Digestive System, Epithelium, Fat Body, Female, ferrandon, Fungal, Gene Expression Regulation, Genes, Green Fluorescent Proteins, hoffmann, Insect Proteins, Larva, Luminescent Proteins, M3i, Male, Membrane Glycoproteins, Organ Specificity, Receptors, reichhart, Reporter, Respiratory System, Spores, Toll-Like Receptors, Trachea, Transgenes}, pubstate = {published}, tppubtype = {article} } A hallmark of the systemic antimicrobial response of Drosophila is the synthesis by the fat body of several antimicrobial peptides which are released into the hemolymph in response to a septic injury. One of these peptides, drosomycin, is active primarily against fungi. Using a drosomycin-green fluorescent protein (GFP) reporter gene, we now show that in addition to the fat body, a variety of epithelial tissues that are in direct contact with the external environment, including those of the respiratory, digestive and reproductive tracts, can express the antifungal peptide, suggesting a local response to infections affecting these barrier tissues. As is the case for vertebrate epithelia, insect epithelia appear to be more than passive physical barriers and are likely to constitute an active component of innate immunity. We also show that, in contrast to the systemic antifungal response, this local immune response is independent of the Toll pathway. |
Nicolas, E; Reichhart, Jean-Marc; Hoffmann, Jules A; Lemaitre, Bruno In vivo regulation of the IkappaB homologue cactus during the immune response of Drosophila Article de journal J. Biol. Chem., 273 (17), p. 10463–10469, 1998, ISSN: 0021-9258. Résumé | BibTeX | Étiquettes: Animals, Cell Surface, DNA-Binding Proteins, Gene Expression Regulation, hoffmann, Insect Proteins, Larva, M3i, Membrane Glycoproteins, Phosphoproteins, Proto-Oncogene Proteins, Receptors, reichhart, Signal Transduction, Toll-Like Receptors, Transcription Factor RelB, Transcription Factors @article{nicolas_vivo_1998, title = {In vivo regulation of the IkappaB homologue cactus during the immune response of Drosophila}, author = {E Nicolas and Jean-Marc Reichhart and Jules A Hoffmann and Bruno Lemaitre}, issn = {0021-9258}, year = {1998}, date = {1998-04-01}, journal = {J. Biol. Chem.}, volume = {273}, number = {17}, pages = {10463--10469}, abstract = {The dorsoventral regulatory gene pathway (spätzle/Toll/cactus) controls the expression of several antimicrobial genes during the immune response of Drosophila. This regulatory cascade shows striking similarities with the cytokine-induced activation cascade of NF-kappaB during the inflammatory response in mammals. Here, we have studied the regulation of the IkappaB homologue Cactus in the fat body during the immune response. We observe that the cactus gene is up-regulated in response to immune challenge. Interestingly, the expression of the cactus gene is controlled by the spätzle/Toll/cactus gene pathway, indicating that the cactus gene is autoregulated. We also show that two Cactus isoforms are expressed in the cytoplasm of fat body cells and that they are rapidly degraded and resynthesized after immune challenge. This degradation is also dependent on the Toll signaling pathway. Altogether, our results underline the striking similarities between the regulation of IkappaB and cactus during the immune response.}, keywords = {Animals, Cell Surface, DNA-Binding Proteins, Gene Expression Regulation, hoffmann, Insect Proteins, Larva, M3i, Membrane Glycoproteins, Phosphoproteins, Proto-Oncogene Proteins, Receptors, reichhart, Signal Transduction, Toll-Like Receptors, Transcription Factor RelB, Transcription Factors}, pubstate = {published}, tppubtype = {article} } The dorsoventral regulatory gene pathway (spätzle/Toll/cactus) controls the expression of several antimicrobial genes during the immune response of Drosophila. This regulatory cascade shows striking similarities with the cytokine-induced activation cascade of NF-kappaB during the inflammatory response in mammals. Here, we have studied the regulation of the IkappaB homologue Cactus in the fat body during the immune response. We observe that the cactus gene is up-regulated in response to immune challenge. Interestingly, the expression of the cactus gene is controlled by the spätzle/Toll/cactus gene pathway, indicating that the cactus gene is autoregulated. We also show that two Cactus isoforms are expressed in the cytoplasm of fat body cells and that they are rapidly degraded and resynthesized after immune challenge. This degradation is also dependent on the Toll signaling pathway. Altogether, our results underline the striking similarities between the regulation of IkappaB and cactus during the immune response. |
1996 |
Hoffmann, Jules A; Reichhart, Jean-Marc; Hetru, Charles Innate immunity in higher insects Article de journal Curr. Opin. Immunol., 8 (1), p. 8–13, 1996, ISSN: 0952-7915. Résumé | BibTeX | Étiquettes: Animals, Base Sequence, Cyclic, hoffmann, Immunity, Immunologic, Immunological, Innate, insects, M3i, Models, Peptide Hydrolases, Peptides, Receptors, reichhart @article{hoffmann_innate_1996, title = {Innate immunity in higher insects}, author = {Jules A Hoffmann and Jean-Marc Reichhart and Charles Hetru}, issn = {0952-7915}, year = {1996}, date = {1996-02-01}, journal = {Curr. Opin. Immunol.}, volume = {8}, number = {1}, pages = {8--13}, abstract = {The hallmark of the innate immune response of higher insects is the rapid and transient synthesis of a battery of broad spectrum antimicrobial peptides by the fat body. The control of the genes encoding these peptides involves cis-regulatory promoter elements homologous to sequences functional in mammalian acute-phase genes. Study of immune-deficient mutants of Drosophila has indicated that distinct pathways control the antibacterial and antifungal responses in this species. Novel receptors potentially involved in the initiation of the immune response have been recently characterized.}, keywords = {Animals, Base Sequence, Cyclic, hoffmann, Immunity, Immunologic, Immunological, Innate, insects, M3i, Models, Peptide Hydrolases, Peptides, Receptors, reichhart}, pubstate = {published}, tppubtype = {article} } The hallmark of the innate immune response of higher insects is the rapid and transient synthesis of a battery of broad spectrum antimicrobial peptides by the fat body. The control of the genes encoding these peptides involves cis-regulatory promoter elements homologous to sequences functional in mammalian acute-phase genes. Study of immune-deficient mutants of Drosophila has indicated that distinct pathways control the antibacterial and antifungal responses in this species. Novel receptors potentially involved in the initiation of the immune response have been recently characterized. |
Lemaitre, Bruno; Nicolas, E; Michaut, Lydia; Reichhart, Jean-Marc; Hoffmann, Jules A The dorsoventral regulatory gene cassette spätzle/Toll/cactus controls the potent antifungal response in Drosophila adults Article de journal Cell, 86 (6), p. 973–983, 1996, ISSN: 0092-8674. Résumé | BibTeX | Étiquettes: Animals, Antifungal Agents, Cell Surface, DNA-Binding Proteins, Fungi, Gene Expression, Genes, hoffmann, Insect, Insect Hormones, Insect Proteins, M3i, Membrane Glycoproteins, MHC Class II, Mutation, Mycoses, NF-kappa B, Phosphoproteins, Proteins, Receptors, reichhart, Signal Transduction, Toll-Like Receptors @article{lemaitre_dorsoventral_1996, title = {The dorsoventral regulatory gene cassette spätzle/Toll/cactus controls the potent antifungal response in Drosophila adults}, author = {Bruno Lemaitre and E Nicolas and Lydia Michaut and Jean-Marc Reichhart and Jules A Hoffmann}, issn = {0092-8674}, year = {1996}, date = {1996-01-01}, journal = {Cell}, volume = {86}, number = {6}, pages = {973--983}, abstract = {The cytokine-induced activation cascade of NF-kappaB in mammals and the activation of the morphogen dorsal in Drosophila embryos show striking structural and functional similarities (Toll/IL-1, Cactus/I-kappaB, and dorsal/NF-kappaB). Here we demonstrate that these parallels extend to the immune response of Drosophila. In particular, the intracellular components of the dorsoventral signaling pathway (except for dorsal) and the extracellular Toll ligand, spätzle, control expression of the antifungal peptide gene drosomycin in adults. We also show that mutations in the Toll signaling pathway dramatically reduce survival after fungal infection. Antibacterial genes are induced either by a distinct pathway involving the immune deficiency gene (imd) or by combined activation of both imd and dorsoventral pathways.}, keywords = {Animals, Antifungal Agents, Cell Surface, DNA-Binding Proteins, Fungi, Gene Expression, Genes, hoffmann, Insect, Insect Hormones, Insect Proteins, M3i, Membrane Glycoproteins, MHC Class II, Mutation, Mycoses, NF-kappa B, Phosphoproteins, Proteins, Receptors, reichhart, Signal Transduction, Toll-Like Receptors}, pubstate = {published}, tppubtype = {article} } The cytokine-induced activation cascade of NF-kappaB in mammals and the activation of the morphogen dorsal in Drosophila embryos show striking structural and functional similarities (Toll/IL-1, Cactus/I-kappaB, and dorsal/NF-kappaB). Here we demonstrate that these parallels extend to the immune response of Drosophila. In particular, the intracellular components of the dorsoventral signaling pathway (except for dorsal) and the extracellular Toll ligand, spätzle, control expression of the antifungal peptide gene drosomycin in adults. We also show that mutations in the Toll signaling pathway dramatically reduce survival after fungal infection. Antibacterial genes are induced either by a distinct pathway involving the immune deficiency gene (imd) or by combined activation of both imd and dorsoventral pathways. |